The problem that the output power of the chassis does not match the external characteristic curve of the eddy current dynamometer during the low speed detection of the mining light rubber tire vehicle is researched.The mathematical model of the driving resistance power of the rubber tire vehicle and the absorbed power of the eddy current dynamometer was established. The eddy current dynamometer was analyzed by parameterization and the external characteristic curve was obtained. The COMSOL software was used to simulate the electromagnetic simulation of different turntable materials. The effects of air gap length, stator pole pairs, excitation current and turntable material on the absorbed power and critical speed of eddy current dynamometer were analyzed. The results show that changing the stator pole number of the eddy current dynamometer and using different turntable materials have a significant influence on the external characteristic curve.