Abstract: Response surface methodology was used to optimize sterilization process for maize Aspergillus niger by microwave irradiation.Microwave power, microwave time and loads of maize on log reduction period of Aspergillus niger spores and crack rate of maize were studied, and corresponding regression models were established. The optimal technological conditions were determined as follows: microwave power of 119W, microwave time of 6min, load of maize of 50g. Under these conditions, log reduction of CFU of Aspergillus niger spores was 1.3769, and maize crack rate was 0. Tested and predicted value were similar basically. The results provides theoretical references for killing maize Aspergillus niger by microwave treatment.