The infrared simulation technology of resistance array has been developed into an established infrared imaging simulation method, which not only has a larger scale but also employs a higher level of manufacturing technology. Large-scale commercial resistor array devices have been developed and applied in the development of several weapon systems, especially in foreign countries. Domestically, considerable progress has been made in this aspect, but some legacy issues related to research on traditional nonuniformity testing methods have not been well resolved. For example, Moiré fringes, edge effects, mapping, and alignment problems appear in experiments, and few researchers have proposed detailed and feasible treatment measures. In this study, an iterative nonuniformity test method based on point spread function estimation is proposed for solving the problems of Moiré fringes and edge effects. In addition, the simulation verification of the mapping ratio exceeding 1:1 is carried out. The effects of different mapping ratios and nonuniformities on the correction effect are compared, and the theoretical basis for the next experiment in this study is given.