It is an economic and reliable means to reduce distribution network loss through distribution network reconfiguration. On the one hand, there is little literature on how to reduce the number of switching actions while reducing the network loss. On the other hand, most of the reconstruction algorithms are difficult to guarantee the global optimal solution. Therefore, in order to solve the above problems, a multi-period dynamic reconstruction method based on second-order cone relaxation is proposed. Firstly, considering the switching state quantity as the optimization variable, the maximized network loss as the optimization goal, and the multi-period dynamic reconstruction model of the distribution network is established. Then, the reconstruction problem is further transformed into the mixed integer second-order cone programming problem. Furthermore, second-order conic programming method is used to solve the model to obtain the optimal dynamic topology of the distribution network. On this basis, similar switching states are merged to avoid frequent changes in the grid structure. Finally, taking IEEE33 bus distribution system as an example, the simulation results show that the effectiveness and superiority of the proposed method are verified.