The accurate thrust measurement has important application in the fields of satellite attitude control and gravitational wave detection, which has become a key issue limiting the development of thruster technology. Many related studies have been carried out at home and abroad. But, it is still difficult to balance heavy loads with high accuracy. In this article, we propose a measurement method based on parallelogram mechanism and build a thrust measurement device to address the problem of difficult thrust measurement of small thrust-to-weight ratio thrusters. It has advantages of high load carrying capacity, high accuracy and good stability. The parallelogram mechanism acts as both a thruster load-bearing component and an elastic element that converts the thrust into a single-degree-of-freedom linear displacement. The micro-displacement is measured by a laser interferometer. Then, the force value to be measured is calculated based on the Hooke′s law. The mechanical response of the device is tested by using electromagnetic force. Experimental results show that the minimum force value that can be resolved by the measurement system is 17. 2 μN with a range of 17. 2 ~ 2 789. 9 μN and a relative uncertainty of 1. 26% at an actual load-bearing capacity of 2. 5 kg. The method is applicable to the measurement of thrust and is of great importance to the development of thruster technology.