Abstract: The traditional passive lower limb prosthetic design process is heavily dependent on human-subject testing, which involves subjective factors of the test subject and makes the test results difficult to reproduce. In response to this, this paper designs a passive lower limb prosthetic testing platform that has two independent degrees of freedom of motion and can evaluate the mechanical properties of most commercially available passive lower limb prosthetics. The drive system was designed using an FPGA+ARM architecture, enabling this testing platform to simulate full gait motion across multiple movement patterns. Concurrent mechanical structure design, control system design, and drive system design were undertaken, allowing the platform to conduct both static and dynamic loading tests. It can assess the verification strength, ultimate strength, and fatigue strength of passive lower limb prostheses in accordance with the requirements of the national standard GB/T 31181-2014.