Abstract: In order to meet the requirement of lightweight and high strength, spacecrafts have an urgent need for density testing of metal, non-metal and composite materials. Considering the limitation of space size and range of scales, a density test device by 3D printing was innovatively simulated and designed, and the density test device with light weight and high strength was successfully developed. The accuracy and reliability of the testing results of the device were verified by experiments. The repeatability and reproducibility of the test data can meet the requirements of the standard. This technology achieves good results in both economic and technical levels by enhancing testing efficiency.