In this paper, in-situ calibration technology of six-dimension force measurement units for the low impact docking mechanism (LIDM)docking performance test-bed is studied. According to the working principle of the six-dimension force measurement unit and test structure characteristics of the test-bed, the research of in-situ calibration method for the measurement unit is carried out. The high-precision standard force loading mechanism is designed based on servo motor controller and force transmission mechanism of planetary screw structure, and a six-dimension force measuring tooling with portability, fine tuning and accurate positioning is built to solve the technical difficulties about smooth loading and benchmark consistency for the in-situ calibration. The research and implementation of the in-situ calibration device for the six-dimension force measurement unit can realize the traceability of six-dimension force parameter of LIDM docking performance test-bed.