The utility model relates to a microgrid adopting a bidirectional relay protective device. Under a condition that the microgrid has a grid connection need, a main controller sends a command to the bidirectional relay protective device and an energy storage inverter at the same time through communication. The energy storage inverter adjusts amplitude, phase angle, and frequency of a microgrid system and the bidirectional relay protective device detects whether voltages, amplitudes and phases and the like at two sides of a grid connection contactor and after it is detected that all the parameters are completely identical, the bidirectional relay protective device sends a grid connection instruction to the grid connection contactor so that reliable microgrid connection is realized and the microgrid connection control method is simple and reliable and effectively reduces impacts on the grid and grid connection contactor. The microgrid connection control method is simple and reliable and capable of shortening reaction and execution time of control signals so that reliability of microgrid connection is improved significantly and impacts of intensive current on the grid connection contactor and the grid during grid connection are reduced.