This paper presents the way to solve interference prob1cm in force measurement by hard-pedestal balancing machine. According to use adaptive filter theory and choose LMS algorithm to train adaptive filter weighting values. To provide the method to solve the interference problem in rotor vibration force measurement that we can get real rotor vibration signal without interference. After calculation, the phase and magnitude of the vibration signal can he estimated. This estimation is verified by numerical simulation and balance experiment of fans.