diff --git a/src/MaaCore/Task/Fight/StageDropsTaskPlugin.cpp b/src/MaaCore/Task/Fight/StageDropsTaskPlugin.cpp
index 754f73557e..7c50dc70f8 100644
--- a/src/MaaCore/Task/Fight/StageDropsTaskPlugin.cpp
+++ b/src/MaaCore/Task/Fight/StageDropsTaskPlugin.cpp
@@ -4,7 +4,9 @@
 #include <regex>
 #include <thread>
 
+#include "Common/AsstTypes.h"
 #include "Common/AsstVersion.h"
+#include "Config/GeneralConfig.h"
 #include "Config/Miscellaneous/ItemConfig.h"
 #include "Config/Miscellaneous/StageDropsConfig.h"
 #include "Config/TaskData.h"
@@ -13,6 +15,7 @@
 #include "Task/ProcessTask.h"
 #include "Task/ReportDataTask.h"
 #include "Utils/Logger.hpp"
+#include "Vision/Matcher.h"
 #include "Vision/Miscellaneous/StageDropsImageAnalyzer.h"
 
 bool asst::StageDropsTaskPlugin::verify(AsstMsg msg, const json::value& details) const
@@ -110,7 +113,33 @@ bool asst::StageDropsTaskPlugin::recognize_drops()
     }
 
     StageDropsImageAnalyzer analyzer(ctrler()->get_image());
-    bool ret = analyzer.analyze();
+
+    bool ret = false;
+    while (!need_exit()) {
+        ret = false;
+
+        // more materials to reveal?
+
+        auto swipe_begin = Point { WindowWidthDefault - 40, 632 };
+
+        const int swipe_dist = 200;
+        ctrler()->swipe(swipe_begin, swipe_begin + swipe_dist * Point::left(), 500, true, 2, 0);
+        sleep(Config.get_options().task_delay * 3);
+
+        auto new_img = ctrler()->get_image();
+
+        const auto offset_opt = analyzer.merge_image(new_img);
+        if (!offset_opt.has_value()) break;
+        const auto offset = offset_opt.value();
+        Log.trace("new image offset:", offset);
+        if (offset <= 4) {
+            ret = true;
+            break;
+        }
+    }
+
+    // image strip constructed, start main step
+    ret &= analyzer.analyze();
 
     auto&& [code, difficulty] = analyzer.get_stage_key();
     m_stage_code = std::move(code);
diff --git a/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.cpp b/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.cpp
index d5684eb3b8..3120ea627f 100644
--- a/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.cpp
+++ b/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.cpp
@@ -1,6 +1,7 @@
 #include "StageDropsImageAnalyzer.h"
 
 #include <numbers>
+#include <opencv2/core/mat.hpp>
 #include <regex>
 
 #include "Utils/Ranges.hpp"
@@ -361,10 +362,41 @@ bool asst::StageDropsImageAnalyzer::analyze_drops_for_12()
     return !flag_analyzer.analyze();
 }
 
+std::optional<int> asst::StageDropsImageAnalyzer::merge_image(const cv::Mat& new_img)
+{
+    LogTraceFunction;
+
+    const cv::Rect ref_roi = { m_image.cols - 320, 530, 280, 100 };
+    Matcher offset_match(new_img(cv::Rect { 0, ref_roi.y, new_img.cols, ref_roi.height }));
+    offset_match.set_templ(m_image(ref_roi));
+    offset_match.set_threshold(0.7);
+    if (!offset_match.analyze()) {
+        Log.error("Unable to merge images");
+        return std::nullopt;
+    }
+    const int offset = (new_img.cols - offset_match.get_result().rect.x) - (m_image.cols - ref_roi.x);
+
+    const int rel_x = offset + m_image.cols - new_img.cols;
+
+    const cv::Rect overlay_rect = { 540, 500, 740, 220 };
+    cv::Rect overlay_rect_on_strip = overlay_rect;
+    overlay_rect_on_strip.x += rel_x;
+
+    cv::Mat new_strip = cv::Mat { m_image.rows, overlay_rect_on_strip.br().x, m_image.type(), cv::Scalar(0) };
+    m_image.copyTo(new_strip(cv::Rect { 0, 0, m_image.cols, m_image.rows }));
+    new_img(overlay_rect).copyTo(new_strip(overlay_rect_on_strip));
+
+    m_image = new_strip;
+
+    return offset;
+}
+
 bool asst::StageDropsImageAnalyzer::analyze_baseline()
 {
     LogTraceFunction;
 
+    m_baseline.clear();
+
     auto task_ptr = Task.get<MatchTaskInfo>("StageDrops-BaseLine");
 
     cv::Mat preprocessed_roi;
@@ -386,7 +418,9 @@ bool asst::StageDropsImageAnalyzer::analyze_baseline()
                          cv::getStructuringElement(cv::MORPH_RECT, { 3, 1 }));
 
         // cropping after derivatives, dilation, and erosion
-        cv::cvtColor(preprocessed_roi(make_rect<cv::Rect>(task_ptr->roi)), preprocessed_roi, cv::COLOR_BGR2GRAY);
+        auto roi = make_rect<cv::Rect>(task_ptr->roi);
+        roi.width = WindowWidthDefault - roi.br().x + m_image.cols; // image may be wider than 1280
+        cv::cvtColor(preprocessed_roi(roi), preprocessed_roi, cv::COLOR_BGR2GRAY);
     }
 
     cv::Mat preprocessed_bin;
@@ -457,6 +491,10 @@ bool asst::StageDropsImageAnalyzer::analyze_baseline()
         Log.trace(__FUNCTION__, "baseline", key.to_string());
     }
 
+    if (m_image.cols - (x_offset + bounding_rect.width) < 30 + max_spacing) {
+        Log.trace("bounding_rect.right=", x_offset + bounding_rect.width, ", more materials to reveal?");
+    } // TODO: else tell caller to prevent unnecessary swipe
+
     return !m_baseline.empty();
 }
 
diff --git a/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.h b/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.h
index 15b0133bc0..322f891032 100644
--- a/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.h
+++ b/src/MaaCore/Vision/Miscellaneous/StageDropsImageAnalyzer.h
@@ -23,6 +23,11 @@ namespace asst
         // <drop_type, <item_id, quantity>>
         const auto& get_drops() const noexcept { return m_drops; }
 
+        // merge a new image with a different material position into m_image
+        // might resize m_image.
+        // return offset in pixels
+        std::optional<int> merge_image(const cv::Mat& new_img);
+
     protected:
         bool analyze_stage_code();
         bool analyze_times();