The rural field road in Chongqing hilly region could not adapt to the development of agricutural mechanization. Taking Dashi Town in Hechuan County as the research object, in this paper the pavement load fatigue stress and temperature fatigue stress theories were applied to optimize the pavement design of rural field road. The research result showed that the standard axle load of agriculture machine was 145 times per day and the cumulative action number of the standard axle load was 1 128 200. When the concrete pavement thickness of the rural field road is 0.18 m , the research for the pavement showed that the load fatigue stress ( σ_pr) and the temperature fatigue stress ( σ_tr) are 3.75, 0.32, respectively, the numerical value r r ( σ_pr + σ_tr ) is 4.36, which is less than the flexural tensile strength. When the concrete thickness is 0.16 m , the load fatigue stress ( σ_pr) and the temperature fatigue stress ( σ_tr) are 4.42, 0.12, respectively, and r r ( σ_pr + σ _tr) is 4.86, which is beyond the flexural tensile strength. Consequently, it is concluded that the least thickness of cement concrete is 0.18 m , and the maximum is 0.22 m . At the same time, cement stabilized aggregates with size of 0.18m are used as the base material of road and rubbles with size of 0.20 m are used as the cushion material. So the road structure could preferably bear the comprehensive action from the load and temperature fatigue stress.