1. An image depth perception device, comprising: an image adaptive pre-processing sub-module, a block-matching motion estimation sub-module, a depth calculating sub-module and a memory, wherein an inputted speckle image sequence obtained and collected by an external image sensor is outputted to the image adaptive pre-processing sub-module in a digital video format; the image adaptive pre-processing sub-module processes adaptive and uniformpre-processing on the inputted speckle image sequence with different characteristics of brightness, signal to noise ratio and size; a standard speckle image with known depth and range information, which is processed by pre-processing, is permanently stored in the memory; the block-matching motion estimation sub-module compares each inputted speckle image in the inputted speckle image sequence processed by pre-processing with the standard speckle image, and calculates displacement of image blocks in the inputted speckle image; and according to the displacement of the image blocks in the inputted speckle image, the depth calculating sub-module calculates depth information thereof, so as to obtain a calculated depth image sequence.