The invention relates to a device and method for detecting the dynamic properties of a two-dimensional directional mirror. The device comprises a dynamic photoelectric autocollimator, a controller of the dynamic photoelectric autocollimator, a hollow rotary platform, a controller of the hollow rotary platform, a rotary target, an adjustment platform, a data acquiring and processing system and a computer measurement and control system. Under the guidance of the computer measurement and control system, a target simulation reflector on the rotary target is driven by the rotary platform to simulate an optical target in movement, the dynamic photoelectric autocollimator provides the rapid and high-precision angle miss distance for the two-dimensional directional mirror, the data acquiring and processing system feeds back and controls the two-dimensional directional mirror to track the target simulation movement in real time, and the computer measurement and control system processes the measurement data of the photoelectric autocollimator in real time to obtain the data reflecting the dynamic response properties of the two-dimensional directional mirror. The device and method provided by the invention can be used for detection of properties of the two-dimensional directional mirror, such as axis shaking, step response, dynamic continuous tracking and the like.