A current protection setting optimization scheme is proposed to address misoperation caused by the overlapping protection zones of the instantaneous section protection in a multi-level current protection system for radiating distribution networks. First, a protection setting optimization mathematical model is established by taking the shortest overall fault-removal time, the highest protection sensitivity, and the least load affected by the fault as the objective function and considering constraints such as the mutual coordination between up- and down-stream line protections. Then, a constrained multi-objective backbone particle swarm algorithm and the K-means clustering algorithm are employed to address the problem, analyze the features of the optimal solutions and select the final optimal solution. Second, aiming at the dead-zone problem of the specific topology screening without final optimization solution, a solution of adding the location optimization of the circuit breaker in the main line is proposed. Finally, the simulation results in Matlab show that the proposed scheme can overcome protection mismatches, adapt to different network structures, and improve the overall performance of distribution network protection effectively.