Soft normally open point（SNOP） refers to a novel power electronic device with the capability of real-time power adjustment

which is usually to replace a tie switch and responsible for active power transfer in normal conditions and for voltage regulation if needed. Firstly

sequential voltage regulation model of SNOP is established

and it is essentially a large scale nonlinear optimization problem

bringing a challenge for solving the problem. Secondly

a method is proposed to change the model into a solvable form by second-order cone programming（SOCP）

solving the problems quickly. Finally

case studies on IEEE 33-node system verify the effectiveness of the proposed model and the method. The utilization of SNOP for voltage regulation in active distribution network can effectively reduce the voltage fluctuations and decrease the network loss. The solving method based on SOCP can ensure solving optimality and greatly improve computational efficiency.