In order to solve the problem of inaccuracy in the application of annubar to gas-liquid two-phase flow rate measurement, an improved method is proposed in this paper to determine the stagnation pressure holes of annubar according to the velocity profile of two-phase pipe flow. Based on the data mcasured in vertical upward two-phase pipe flow, the calculating method and result are given, this method can improve both the accuracy and the applicability of annubar.