The Despite the importance of weight distribution in military backpacks, there is a lack of devices and protocols to measure its performance objectively. In this research, we designed a method to objectively measure and evaluate the weight distribution performance in a backpack, based on the design rationale of average human body dimensions. This paper also includes verifying whether the above device and protocol can measure and evaluate the weight distribution performance using a genuine military backpack with a weight distribution function for special forces. The device and protocol to measure weight distribution performance designed in this research can provide a basis for ergonomically testing the weight distribution performance of military backpacks.