The tractor traction performance is closely related to the distribution of the tractor's total weight on the front and rear axles. For the rear wheel drive tractor, it is one of the effective ways to improve the tire-soil adhesion state so as to promote the traction performance of the tractor by reasonably selecting the ballast weight for the drive axle and optimizing the axle load distribution between the front and rear axles. A position-adapted battery ballast frame structure was proposed to improve the ballast effect so as to improve the traction performance of the electric tractor. Based on the equations for traction performance prediction, an optimization model of battery ballast parameters was established with the goal of comprehensive optimization of driving efficiency, slip ratio and safety ballast of front axle. The simulation model of electric tractor under the horizontal traction condition with the load range of 1~5kN was built on the Matlab/Simulink platform, and the traction performances before and after the ballast optimization were simulated and analyzed. Referring to the position-adapted battery ballast frame structure, the experimental prototype of electric tractor was designed, and the ballast parameter optimization model was verified by ploughing in the soil tank in the indoor environment. The results showed that under the premise of ensuring the safety ballast of the front axle, the battery layout optimization can improve the traction speed and energy utilization rate by 4.16% and 5.66%, respectively, which effectively improved the traction performance of electric tractor.