Some general methods for nonuniformity correction of infrared focal plane array (IRFPA) were discussed in the article. Multi-point linear algorithm (MPLA) based on black body was used to correct some images of IRFPA with size of 128×128 and the results were rather good. Method for the selection and determining of the number of the used points were analyzed with knowledge of the response curves of the detector because the performance of MPLA was related to these two factors. And the influence of them was also researched practically, which showed the perfect reconciliation with former analysis.