A new recognition system for mixed power quality disturbances is proposed.Firstly， it uses wavelet transform to decompose the de-noised signal into different frequency-space. Secondly， the low-frequency component is analyzed by Teager energy operator（TEO）， in order to distinguish whether the signal contains frequency variation， sag， swell or interruption. Thirdly， Prony algorithm is adopted to study the signal without low-frequency component， and it can estimate the existence of harmonics， inter-harmonics or oscillation transients. Finally， it detects the begin-end instants and windowed disturbance energy of high-frequency component to identify whether it is composed of impulse or notch disturbance. A mass of single disturbances and mixed disturbances are generated for testing the proposed recognition system， and the results show that the system has good adaptability and high recognition rate for those kinds of signals.