Synchronous phasor measurement is a research hot-spot in advanced application to a distribution network. Examining hybrid measurement of a synchronous phasor and smart meter in a distribution network, this paper proposes a state estimation method for the distribution network with branch current as the state variable. In a distribution network with distributed photovoltaic access, the method transforms the μPMU and the smart meter measurement data, and realizes the minimum measurement error of the heterogeneous data branch current amplitude. First, based on the hybrid measurement system, the three-phase measurement equation model is derived. Then, the state estimation of the three-phase branch current is realized by weighted least squares method. The proposed method is applicable to the distribution network of three-phase unbalanced and multi-branch current measurement. Finally, the effectiveness of the method is verified by simulating the IEEE 37-node system with distributed photovoltaics. This work is supported by National Natural Science Foundation of China (No. 51307018) and Science and Technology Project of State Grid Corporation of China (No. 5222LK17001T).