The landing gear is an important part of the aircraft. The strength of its structure directly affects the safety in the take-off and landing process. The landing gear of the aircraft is designed for the strength and rigidity specification. This paper extracts the attitude and motion information during landing process from flight data to analysis ground loads of the landing gear, thus providing reference and input for troubleshooting. The results show three-direction load may be one of the causesfor the damage of landing gear.