Sit-to-stand is an indispensable functional activity in human daily life, which requires high muscle strength, not only to control the lower limbs, but also to ensure the stable ascension of the trunk. This paper describes in detail the trajectory and speed of the joints through the human sit-to-stand test, analyzes the change rule of the angle of the joints, the angular velocity and the position of the center of mass in the human sit-to-stand, and records in detail the change of the plantar pressure of the subjects in this process. Through the study on joint motion and plantar pressure changes in the process of sit-to-stand, this paper summarizes the kinematics of human body in this process, aiming to provide a basis through the results of this paper for the design of human sit-to-stand assistive devices, which may be used in the future to analyze the sit-to-stand state of patients with lower limb disorders, and carry out the corresponding treatment and rehabilitation training.