The stable operation of a variable frequency pump is of great importance to the management of a water supply project. Analyzing the operation performance based on monitoring data is necessary for maintaining the stable operation of a variable frequency pump. Several sensors are installed at six monitoring points on the pump to collect signals including vibration velocity, vibration acceleration and vibration displacement. Monitoring signals are preprocessed by smoothing, adjusting waveform trend and filtering on the basis of Fast Fourier Transform (FFT). Then, the vibration features are extracted by power spectrum analysis and cepstrum analysis methods. According to the extracted features, the vibration law and actual operation performance of a variable frequency pump under different operating conditions are analyzed. Results indicate that the vibration amplitude of the pump varies sharply under the operating conditions of 15 Hz, 20 Hz and 30 Hz, 35 Hz. The operating condition of 0 Hz, 15 Hz is the restricted operating area of the pump. The vibration and noise continue increasing under the operating conditions of 35 Hz, 50 Hz and reach the maximum values at 50 Hz. Therefore, the optimal operating is within the range of 20 Hz, 30 Hz. Finally, by analyzing the critical values of the operating conditions, the fault diagnosis and the evaluation of the operating status are conducted.