To solve the state estimation issue of middle/low voltage distribution network with Distributed Generations (DGs), this paper proposes a state estimation method for the middle/low voltage distribution network with DGs. The equivalent model of transformers is introduced in the middle/low voltage distribution network with DGs. Based on the node current injection equations, the measurement equations are established, which can solve the three-phase three wire system and three-phase four wire system and obtain better application scope and estimation accuracy. Besides, the linear zero injection constraint under the rectangular coordinate is adopted as an equality constraint in the proposed model. It can limit the node injection power to be zero strictly and simplify the calculation process. Finally, Bacteria Colony Chemotaxis (BCC) algorithm is applied to solve the state estimation of the proposed model. The effectiveness of the proposed method has been validated by the modified IEEE 13-bus test system, which demonstrates better estimation accuracy and convergence of the proposed method. This work is supported by National Natural Science Foundation of China (No. 61374098).