When calculating the equivalent parameter to the hub center of helicopter fuselage based on excitation test data， the calculation result would be different with different point-taking schemes， amplitude errors and phase errors. In terms of this issue， the equivalent parameters of the 1st-order mode of transverse motion of a certain type of helicopter with large mass are calculated with different point-taking schemes. The difference between the calculated equivalent mass and equivalent stiffness is significant， and analysis shows that this result is mainly caused by the phase deviation.The computational formulas of equivalent parameters for amplitude error and phase error are derived. After analyzing the formulas， the suggestions of point selection are given as follows： The two points could be selected based on the amplitude of the excited displacement response， and they should be as close to the resonance point as possible. The frequency response curve is calculated using the obtained equivalent parameters and compared with the test data for verification. To avoid the sensitivity to amplitude and phase errors in the calculation of equivalent parameters， the difference in excitation frequencies between the selected two points should not be too small.