The invention discloses a PLIF image correction device and method based on a digital image registration technique. The device comprises an Nd: YAG laser, a flaky light beam shaping lens group, a measured target, a reference target, an image intensifying type camera, a computer and a time sequence control system, wherein the time sequence control system is used for synchronizing a pumping laser and the image intensifying type camera, so that the opening time of the image intensifying type camera is synchronous with the fluorescence time of the tested target; noise interference caused by non-tested signals is filtered out; the computer is used for recording acquired PLIF images and implementing digital image registration correction. By adopting the method that image distortion is eliminated by using the digital image registration technique, the problem that various optical measuring methods have conflict as the PLIF technique has requirements on the measuring machine position when other optical measuring methods are combined for on-line measurement is solved, and the flexibility of applying the PILF technique to on-line measurement is greatly improved.