The support system of wind tunnel model has large motor power and complex operating environmentthus the balance signal is influenced seriously by motor electromagnetic interferencewhich may affect the accuracy of experimental data.To solve the problema technology for interference signal processing based on wavelet reconstruction is proposed.Firstlythe frequency threshold of wavelet reconstruction is determined based on the balance step test principle.Thenwavelet basis of db10 is usedwhich divides the signal wavelet into 10 layers.Analysis is made to each layer by Fast Fourier Transform (FFT)the signals under 1 Hz are reservedand thus signal reconstruction is realized.Through the use of wavelet reconstruction technologyElectromagnetic Interference (EMI) is significantly suppressed and the accuracy of the processed data meets the requirement on experimental accuracy.