Abstract: Based on minimum resolvable temperature difference(MRTD) channel width of thermal imaging systems and modulating transfer function(MTF) channel width of photoelectronic imaging systems,a comparative research between the evaluation methods for the general performance of thermal imaging systems is studied through simulation and experiments for an actual thermal imaging system.Good agreement was drawn between the two methods for the general performance valuation of thermal imaging systems.Some main system parameters were analyzed on their influence for the evaluation methods,indicating that the optimal angular magnification described by the two evaluation methods were consistent with the actual systems,and that the evaluation method based on MRTD channel width has a better agreement with actual viewing which is thus more suitable for evaluating thermal imaging systems.The comparative result is of significance for developing evaluation theory of photoelectronic imaging systems,and can provide direction more promisingly for the design of practical systems.