In order to improve the shift quality of the power reversing tractor, the parameter configuration of the gearbox wet clutch was studied in this paper. Firstly, the transmission principle of the power reversing tractor was introduced; then, the mathematical model of the key parts such as wet clutch, proportional pressure reducing valve and the whole tractor were constructed; thirdly, four clutch control parameters affecting the shift quality were determined, namely, the instruction time $t_{1}$∼$t_{3}$ and the instruction voltage $V_{1}$ of the proportional pressure reducing valve, and the shift quality evaluation index used in this study was determined. Finally, based on four factors and three levels orthogonal test method, the clutch control parameters under different conditions were optimized. The results show that: with the increase of gear, the values of $t_{2}$ and $V_{1}$ should be moderately increased; $t_{1}$ should be larger under any working conditions; $t_{3}$ should be smaller in high or low gear, otherwise the value level should be increased moderately; the driver should try to use power shift at lower gear and engine speed.