The invention provides a rotor system typical fault diagnosis method based on motor current, belonging to the field of rotating machinery equipment. According to the method, firstly a current signal of a rotor system driving motor is collected, and an improved wavelet threshold denoising method is used for current signal denoising pretreatment on the current signal; then the current signal is subjected to EEMD decomposition, an meaningless IMF component is removed, the amplitude domain and time-frequency domain feature of each IMF component are extracted to form a feature vector, then a principal component analysis method is used to carry out dimension reduction on the feature vector, and a new low dimensional feature vector is obtained; and finally a support vector machine of particle swarm optimization is used to establish a nonlinear mapping relationship between the feature vector and different fault types, and the fault diagnosis is realized. According to the method, through the fault diagnosis of the motor current signal, the signal collection is convenient, the external interference resistance ability is high, and the method is easy to implement. The invention can be applied to the diagnosis of faults of mass unbalance, deflection angle misalignment, parallel misalignment and the like of a rotor system.