It is of great help to take proper anticipatory actions to eliminate the disturbances that identifying disturbances timely and accurate, avoiding blackouts. In this paper, the wavelet multi-resolution analysis based method is introduced to identify power system disturbances. The effectiveness of the method is addressed by applying to a real power system in Western China. After that, based on the method, a software system based on the proposed method is developed. In this paper, the design and implementation of the system is introduced. The system receives real-time frequency signals from wide area measurement system (WAMS), identifying disturbances online. The system has been running in actual power system, achieving engineering application. The measured disturbances further validate the effectiveness and feasibility of the method and software.