An experimental study was carried out in this article to investigate the transient operat-ing performance of a Dual Compensation Chamber Loop Heat Pipe (DCCLHP) with Thermoelec-tric Cooler (TEC) under acceleration conditions and ammonia was selected as the working fluid. For the purpose of comparison, experimental work was conducted under terrestrial gravity. Sensi-tivity analysis was performed to explore the effect of several control parameters such as the heat load, acceleration magnitude and TEC assist on the startup and operating performance of the DCCLHP. Experimental results indicate that the DCCLHP can get to a steady-state operation when the heat load changes from 25 W to 300 W under terrestrial gravity. While under acceleration conditions, the DCCLHP can work at a high operating temperature or even fail to operate, which shows the acceleration effect plays a significant impact on the loop operation. The TEC assist with power of 10 W can improve the operating performance and reduce the operating temperature for the case of small heat load and acceleration magnitude. When the acceleration exceeds 3g at large heat load, the effect of TEC assist on the operation at large heat load can be ignored.