A new technique of time domain 2 dimensional fluorescence lifetime microscopic measurement is presented. A fluorescence lifetime imaging microscope system and data processing method of this technique are described. Reference sample is used to test the system. Experimental results show that the temporal resolution of the system is 2 ps. When magnification of the microscope is 100, the spatial resolution is 8 μm. When a finer mask and a micro shift mechanical system are used, spatial resolution of less than 1 μm can be obtained.