Abstract: To optimize the empirical constants in dynamic stall model and improve the prediction accuracy of airfoil aerodynamic performance when dynamic stall occurs, the influence of pressure lag and boundary layer lag time constant on the dynamic stall performance is explored, using the B-L dynamic stall model and the wind tunnel experiment in the Key Laboratory of Wind and Solar Energy Utilization Technology of the Ministry of Education at Inner Mongolia University of Technology. The main conclusions are as follows. The time constants of pressure lag and boundary layer lag have great influence on the dynamic lift coefficient, which is related to the average angle of attack. When the average angle of attack is relatively small and the flow is between the attached flow and the separated flow, appropriately reducing the time constant can make the calculated results of the dynamic stall model closer to the experimental values. When the average angle of attack is relatively large and the flow is in separated flow or completely separated flow, the time constant value can be appropriately increased. The influence of pressure lag and boundary layer lag time constant on the dynamic drag coefficient is not significant. The dynamic lift coefficient only decreases with the increase of boundary layer lag time constant in the completely separated flow process where the angle of attack decreases gradually.