The invention provides a device and method for detecting aerial photography camera exposure delay time, and belongs to the field of aerial photography camera calibration and detection. The device and method aim to solve the problems that in the prior art, ground control points need to be laid and imaging precision is low. An FPGA master controller controls a light source to light by means of a light source drive, and light is radiated to a DMD after penetrating through an illumination optical system and a beam splitter prism; the FPGA master controller controls the DMD to produce light modulation signal through a DMD drive circuit and sends out an exposure pulse control signal to an aerial photography camera through an exposure pulse port; image information collected by the aerial photography camera is sent to the FPGA master controller, and the FPGA master controller transmits image grey information and delay time information to a portable computer through an RS 422 port circuit. Delay time Td of time when the DMD is turned to be at 12 degrees relative to the moment when the exposure pulse control signal is sent reflects exposure delay time of the aerial photography camera.