According to the short duration and fast change rate of transient power disturbance, a transient power disturbance detection method based on wavelet transform is proposed. Using db4 wavelet, the method realizes transient power signal sampling and multi-scale decomposition, and then judges the signal break points. It can accurately detect and locate the common transient power distanbance problems in distribution network and is also compared with other-order db wavelet transform result. The simulation results show that this method can identify and locate transient power disturbance signals quickly and accurately, it has high precision and can meet the actual engineering requirements.