HY-2A scanning microwave radiometer cold shy calibration method and Geophysical parameters retrieval algorithm were studied. According to HY-2A satellite scanning microwave radiometer on observation and scanning design principle and observation geometry, the earth's signal into cold reflector based on the earth observation data of microwave radiometer was corrected, and cold sky reflector weight coefficient matrix by the ground observation brightness temperature to correction cold sky observation signal was established. Based on the sea surface temperature, sea surface wind speed, moisture content and cloud liquid content and microwave radiometer radiative transfer model, HY-2A scanning microwave radiometer model theory brightness temperature under different conditions of each frequency and polarization was calculated, and a linear regression model was established to fit different geophysical parameters retrieval coefficient, using multiple linear regression algorithm retrieving HY-2A microwave scanning radiometer geophysical parameters, compared to international microwave radiometer data, and the product accuracy was obtained.