This paper uses quadric orthogonal rotating combination design test, obtains the cohesive force changes value after given many times freeze-thaw cycles for the geogrid-reinforced clay with different reinforcement spacing, moisture content and degree of compaction. Through analysis of the mathematical calculation and test data to get the regression equation about the value of related with reinforcement spacing, fillers compaction degree and initial moisture content, and test the conspicuousness about the equation and the influence factors. Applies the equation to calculate the value of cohesive force in the else test conditions, the results show that the test results and the calculated values fit well, the equation can be used to calculate the cohesive force of geogrid-reinforced clay after many times of freeze-thaw cycles. The regression equation provides a theoretical reference for the engineering practice.