The Verification, Validation and Accreditation (VV&A) technology is used in an infrared target simulator system and the VV&A operation mode of the infrared target simulator system is studied. Then, a property system is built according to a point target simulator. The fidelity of the simulator system is evaluated. The result shows that this method is feasible. It can use the fidelity definition flexibly and evaluate the credibility of the simulator indirectly.