In order to satisfy the demand of disturbance compensation for airborne platform mounted on multi-rotor unmanned aerial vehicles (mUAV),a composite method of disturbance c ompensation which combines vibration damper with servo controller based on improved disturbance observer (IDO) is propose d.After the in-depth analysis of the improved disturbance observer ability of disturbance compensation and ability of robustne ss,the construction of the servo control system based on the improved disturbance observer is designed.The structural p arameters of vibration damper and the installation position are presented according to the vibration characteris tics of airborne platform which is mounted on multi-rotor unmanned aerial vehicles.The flight experiment shows that after int roducing composite disturbance compensation method,the line of sight (LOS) error is reduced to 0.03°,and the vibration isol ation i s increased by about 15dB.The composite disturbance compensation method can compensate the disturbance of airborne platf orm effectively,and the method can satisfy the disturbance compensation demand of airborne platform which is mounte d on multi-rotor unmanned aerial vehicles completely.