In order to solve the problem of instability and failure of soil slope in spring thaw period, a test scheme combining TMS9018-500 frost heave cycle test chamber and UU triaxial shear instrument was adopted to obtain soil shear strength parameters under different freeze-thaw cycles. Based on the coupling theory of frozen soil water-heat-force, numerical simulation of soil slope in spring thaw period was carried out by COMSOL multi-physical finite element software. The development law of the number of freeze-thaw cycles on the potential slip surface, displacement and safety factor of soil slope in spring thaw period was analyzed. The results show that with the increase of the number of freeze-thaw cycles, the equivalent plastic strain of the soil slope during spring thaw period increases, the equivalent plastic strain at the foot of the slope is relatively concentrated, and the potential sliding through area develops from the foot of the slope to the top of the slope. With the increase of the number of freeze-thaw cycles, the displacement of the soil body in the shallow positive thaw area of the soil slope increases gradually, and the coefficient of safety decreases, and the maximum decrease is about 37.86%, which shows that the freeze-thaw cycles make the soil slope during spring thaw period more and more unfavorable to stability. This indicates that the freezing and thawing cycle makes the soil slope more and more unfavorable in the spring thawing period. The research results are of great significance for the slope protection infrastructure construction in spring thaw period.