In the pressure test, the presence of the piezometric tube will distort the pressure signal. Through the actual measurement of the frequency response function of the measuring system, the influence law of the piezometric tube on the signal is obtained, and the shortcomings of the "B-T theory" are revealed. Based on this, under the actual turbulent flow, the influence of the piezometric tube length on pressure data of a single measuring point and overall force of model is studied, and the correction effect of the "B-T theory" is verified. The results show that for single-point pressure data, the piezometric tube will not affect the data mean and variation coefficient, the standard deviation increases first and then decreases as the tube length increases, the signal time domain approaches the mean value as the tube length increases, the phase keeps lagging, and the signal frequency domain value gradually deviates from the true value with the increase of tube length and frequency. For the overall force of model, the overall resistance, the correlation and coherence of each force can be regarded as not affected by the piezometric tube, the change rule of force spectrum is the same as that of frequency domain value of single measuring point. "B-T theory" has a poor correction effect in the signal time domain, and performs well in the frequency domain correction.