In order to solve the problem of limited control range of control elements and scattered control pattern of distribution networks, Power Flow Router (PFR) is applied in distribution networks. An improved branch flow model with power flow routers in distribution networks is proposed and an optimal power flow model including PFR is constructed. Second-order cone relaxation is used to relax the model and the relaxed model is solved by using the commercial algorithm package such as Gurobi. Furthermore, a method, which considers the uncertainty of load and distributed generation’s output, is presented based on the combination of Latin hypercube sampling and second-order cone programming. The revised IEEE 33-bus system verifies the effectiveness of the proposed method. This work is supported by National Natural Science Foundation of China (No. 51467012).