Abstract: Active distribution grid with tie switches has a complex grid structure and undergo frequent changes in operation mode, which greatly affects the correct operation of traditional current protection that relies on static grid topology and fixed operation mode. A setting optimization scheme for instantaneous overcurrent protection is proposed, which monitors the switch status information in real-time by the terminal unit, uploads the topology correlation matrix to the master station, and combines the output characteristics of the inverter-type distributed power supply to adaptively adjust the protection settings. The scheme can effectively enhance the adaptability of the protection to the grid topology and the output fluctuation of the inverter-type power supply with low communication pressure. Simulation results show that it can effectively increase the instantaneous overcurrent protection range, reduce the impact of DG output and better adapt to grid topology changes.