Multipurpose, intelligent, and strong terrain adaptability are important trends in the development of helicopters in the future. The landing gear is a key component to ensure the safety of helicopter takeoff and landing. Due to the poor terrain adapt-ability of the traditional landing gear, a leg landing gear system is designed using the bionics design concept to solve the problem of the helicopter"s smooth land observation in complex terrain environment. Starting from the design require-ments of leg landing gear, the landing architecture was analyzed and the leg structure design was completed. Then, based on the designed leg mechanism, the kinematics analysis and dynamics analysis are completed, and the relevant models are established as the basis for the motion control of the leg landing gear. Finally, motion testing of the leg landing gear was completed in the laboratory, proving the rationality of the structural design and the accuracy of the control algorithm.