Flap is an important lifting surface of aircraft. In order to obtain accurate flap aerodynamic load, it is necessary to arrange pressure taps on the flaps and carry out wind tunnel tests. Based on the CFD simulation results, the pressure distribution law of a certain type of flap was analyzed, and based on this, the layout scheme of pressure taps scheme for the low-speed wind tunnel test of this type of aircraft flap was optimized. The influence of different interpolation methods on the accuracy of measurement results of vertical force and hinge axis torque was studied. The results show that the pressure nonlinearity near the leading edge is strong; the pressure with chord ratio of 0. 15 ~ 0. 3, 0. 3 ~ 0. 5, 0. 5 ~ 0. 8 and 0. 8 ~ 1 is close to piecewise linear distribution. For this flap, the pressure taps shall be arranged at the chord ratio of 0. 04, 0. 07, 0. 15, 0. 3, 0. 5 and 0. 8. The measurement error of vertical force and hinge axis torque obtained by piecewise linear interpolation of pressure distribution is no more than -13% . The error of cubic spline interpolation method is less than -6% , which is significantly smaller. The proposed layout scheme of pressure taps can significantly improve the accuracy of aerodynamic load measurement in flap low-speed wind tunnel test, and has certain reference significance in the field of flap wind tunnel pressure test design and aerodynamic load measurement.