Analytical geometry is used for analyzing and proofing main calibration methods of L Band Wind Finding Radar systems, such as the zero calibration of antenna azimuth, the perpendicular calibration of the optical axis and the mechanical elevation axis, the parallel calibration of the optical axis and the sea level, the consistent calibration of the optical axis and the electrical axis, etc. The theoretical analysis of these calibration methods is made. Based on the calibration methods and the analytical results, the keys of calibration implementation of L Band Wind Finding Radar systems are summarized. Some shortcomings are analyzed, and the corresponding improvement methods are given. The theoretical analysis may lay a good theoretical basis for technicians to grasp radar calibration methods. The implementation keys may help reduce calibration errors and ensure the reliability of radar detection. The improvement methods can be used as technical references for improving calibration implementation and system device maintenance.