Abstract:In response to the micro-newton thrust measurement requirements for space gravitational wave detection missions, a singlewire torsion micro-newton thrust measurement system based on closed-loop control has been developed. Based on the principle of torsional pendulum micro-newton thrust measurement, the detailed design scheme of the micro-newton thrust measurement device is given, and the twisted wire structure, angular displacement measurement, electromagnetic calibration force, and closed-loop control system are mainly analyzed. The micro-newton thrust measuring device is calibrated through experimental measurement, and finally the error analysis is carried out. The test results show that the torsion wire stiffness is about 0. 003 25 N·m/ rad in the open-loop state, and the error with the theoretical value is about 4. 0%; the thrust measurement range in the closed-loop state is 0. 1 ~ 246. 0 μN, and the minimum resolution is better than 0. 1 μN, which is relatively uncertainty error is 1. 174%, which meets the measurement requirements for the thrust measurement range, resolution and accuracy of micro thrusters.