The present invention discloses a DMD (
digital micromirror device) computing holographic scanning-based 
fully automated TCSPC-FLIM (time-correlated single 
photon counting-
fluorescence lifetime imagingmicroscopy) 
system and a time detection method. According to the DMD (
digital micromirror device) computing holographic scanning-based 
fully automated TCSPC-FLIM 
system and the time detection method,a continuous 
laser excites a sample to generate 
fluorescence under a 
wide field condition; an SCMOS camera transmits obtained sample 
fluorescence information to a computer; the computer performs calculation and 
processing so as to obtain the position and intensity information of a fluorescence image, selectively generates DMD two-dimensional hologram distribution corresponding to a 
region of interest, and at the same time controls a DMD lens group to achieve selective optical excitation; under the control of the computer, a DMD can transmit 
laser light from a first 
laser to the sample througha light 
microscope group, a chromatic dispersion 
elimination system, the DMD and the like, so that the 
laser light can excite the sample to realize FLIM. According to the system of the invention, theDMD is applied to a fully-automated TCSPC-FLIM system; the DMD is adopted as a 
scanner, and is added to an automatic selection 
optical path system; 
fully automated fluorescence service life 
microscopic imaging can be realized according to the definition and selection of a user. With the 
optical path system of the present invention adopted, an imaging scanning speed can be greatly increased, and selective optical excitation is realized, and the fluorescence imaging of a weak fluorescent region can be effectively improved.