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 mechanical structure, control system, and drive system are designed, making the testing platform capable of static loading tests and dynamic loading tests, and allowing the verification strength, limit strength, and fatigue strength of passive lower limb prosthetics to be tested according to the national standard GB/T 31181-2014.