Storage system of original frame of monitor data and storage method thereof

A storage system of original frames of monitor data, comprising:

• a monitor sensor, providing a plurality of original frames;
• an event marking circuit, having an input terminal coupled to the monitor sensor, configured to determine event intensities respectively corresponding to the original frames provided by the monitor sensor, and respectively marking the event intensities on the original frames;
• a data storage circuit, coupled to an output terminal of the event marking circuit, and configured to completely store the original frames marked by the event marking circuit;
• and
• a frame processing circuit, coupled to the data storage circuit, and configured to check the original frames in the data storage circuit according to the event intensities, wherein regarding a plurality of first original frames that the original frames with an existing time falling within a first time section, the frame processing circuit preserves the original frames having an event occurred in the first original frames, and deletes other original frames in the first original frames, and regarding a plurality of second original frames that the original frames with the existing time falling within a second time section, the frame processing circuit preserves the original frames with higher event intensities in the second original frames, and deletes other original frames in the second original frames.