The azimuth and elevation calibration of Lband radar are usually conducted by Polaris and theodolites; however, there is lack of reliable and effective tools to test its correctness.This paper adopts the solar position algorithm with a high degree of accuracy, uses the Python language program to design and package. According to the actual latitude and longitude, solar declination angle, and the time difference of the station, the sun position is calculated in real time to calibrate the radar antenna pointing in theory. The test and tolerance analysis are carried out in several stations, and the accuracy is within 03 degrees，referring to the domestic new generation weather radar antenna beam pointing calibration specifications (≤03 degrees). The accuracy meets the operation requirements.At the same time, the algorithm software can also provide a more efficient way to check the daily radar performance and check whether there are troubles in radar, so to ensure the reliability of sounding data.