Large scale integrations of EVs brings challenges on the security operation of the distribution networks. The Soft Normally Open Point (SNOP) is commonly utilized to replace tieswitch. It not only improves the power flow of both two lines, but also provides the accurate controlling for power flows of the feeders connecting to the SNOP and increase the control flexibility of whole systems. In this paper, sequential probability output models of EVs and loads are established based on the considerations of uncertain characteristics. Furthermore, a multiobjective model of the optimal allocation for SNOPs is proposed. Meanwhile, a corresponding solution is also presented by considering the system losses and uncertain outputs of EVs. Simulation results of an IEEE 33 nodes system are presented to verify the feasibility and validity of the proposed model and algorithm.