The transition resistance affects the fault location in distribution network. For this reason, strong tracking filter is proposed to achieve location of phase to phase short circuit fault. First of all, the short-circuit current and voltage of head-end distribution line is preprocessed by using the wavelet transform in order to eliminate high frequency noise in original signal. The differential equations about fault current and fault transition resistance are established by analyzing the fault loop. The state variable and output variable are properly selected in order to transform the fault circuit’s differential equation to state estimation equation. Then the model state is estimated by using strong tracking filter, thus to achieve fault location. The effectiveness of the algorithm has been verified by the Matlab simulation results. In addition, the preprocessing of short-circuit current and voltage by using the wavelet transform can improve the speed and accuracy of fault location.