Based on the dynamic coupling simulation model of landing gear-tire-wet pavement in consideration of the influence of pavement flatness, the time history curves of tire wheel cardiac displacement at take-off and landing stages are obtained. On this basis, the finite element software is used to simulate and analyze the variation law of supporting force, contact area and displacement resistance of accumulated pavement under dynamic load at landing and takeoff stages, obtaining the dynamic load influence coefficient of critical hydroplaning speed under dynamic load. The results show that the pavement support force, contact area between tire and pavement, displacement resistance and critical hydroplaning speed are all lower than those under static load at take-off and landing stages. At take-off stage, the difference between pavement support force of dynamic and static load is small, the displacement resistance decreases by 0.3~3 kN compared with the static load, and the critical hydroplaning speed decreases within 5.5 km/h; At landing stage, the pavement support force is reduced by 5%~10% compared with the static load, and the corresponding displacement resistance is reduced to the maximum by 50%. The critical hydroplaning speed changes sharply, and the difference is between 5 and 9 km/h. Based on the above-mentioned change law of critical hydroplaning speed, the ratio of critical hydroplaning speed of dynamic and static load is defined as the influence coefficient of dynamic load, and the value of this coefficient is a range from 0.95 to 0.99 under different taxiing conditions; In view of the fact that the critical hydroplaning speed of the aircraft decreases greatly during the landing stage and the hydroplaning risk is higher, the dynamic load influence coefficient is taken as 0.96 for safety.