The surface-source blackbody is widely used in infrared remote sensing and other fields as a calibration source to calibrate infrared loads by providing accurate infrared radiation, and the effective emissivity of the surface-source blackbody is one of the important parameters for the calibration of infrared devices, which directly determines the accuracy of calibration. In this paper, two microarray structure models, ideal and non-ideal cases, are established around the effective emissivity of the surface-source blackbody radiating surface, and simulation experiments based on Monte-Carlo method (MCM)are carried out. The effective emissivity of the blackbody radiation source is analyzed to be influenced by the geometrical parameters of the microcavity structure, the emissivity of the surface coating and different angles. The effective emissivity increases with the decrease of the base height ratio of the pyramidal microcavity structure, and the emissivity of the surface coating material is linearly increasing, and the linearity of the two models is better than 0.9997. The effective emissivity of the ideal and non-ideal models has a small trend in the vertical direction and horizon direction angle 0-±10°, and the standard deviation is less than 0.15%, which has high stability. The results of the study can provide theoretical guidance for the enhancement of the effective emissivity of the surface-source blackbody.