A kind of lower limb bionic joints rehabilitation equipment based on the numerical atlas method is designed. It can make up for the shortcomings of traditional lower limb paraplegia therapy, and realize a single motor driving two joints at the same time, the structure is simple and easy to implement. Through the analysis of normal walking gait, and determine the implementation mechanism of the joint type, the characteristic parameters of the joint implementation mechanism of the long rod is designed and calculated, by FFT (fast Fourier transform) mathematical tool, the characteristic parameters of the output function curve of the mechanism are extracted. The design and calculation of hip joint and knee joint by using Matlab programming, can reach the design goal. The simulation results show that the fitting error of this method can be controlled within 5%, and it will not cause secondary injuries to the patients.