Abstract: Disclosed are a time delay integration (TDI)-based image sensor and an imaging method thereof. The TDI-based image sensor includes: a multi-stage linear array including a plurality of single-stage linear arrays arranged along a scanning direction of the image sensor. Each single-stage linear array includes a plurality of pixels arranged along the linear array direction. Each single-stage linear array enters a count mode in response to a first control signal, and enters a transfer mode in response to a second control signal. In the count mode, each single-stage linear array counts optical signals incident on the pixels and obtains a count value, and in the transfer mode, each single-stage linear array stops counting, except for the last single-stage linear array, other single-stage linear arrays each output the obtained current count value to the next single-stage linear array, and the last single-stage linear array outputs the obtained current count value.