Abstract: In this paper, aiming at the problem that it is difficult for the elderly to stand up when they go to the toilet due to the aging knee joint, a type of automatic aging assistant lifting device is designed based on the virtual prototype technology. The core mechanism and device are designed based on mechanical principle; the three-dimensional model is established by using CROE; and the kinematics model of the virtual prototype is established in multi-body dynamics ADAMS software. The curve of kinematics parameters such as displacement, velocity and acceleration of the specified point is measured, so that the physical prototype can be manufactured in the laboratory for the convenience of subsequent production.