Inverters are basic distributed energy sources in microgrid. According to the need for rapid, frequency, and safe microgrid inverter grid seamless connecting requirement, this paper design a novel implement method for microgrid connecting grid automatically. This method is not only easy to implement, but also has a rapid synchronizing procedure and insensitive to the switch closing delay influence. The relationship between the angle difference and q axis voltage is explored and used to design the control law so that only one PLL module is needed. D axis voltage is also included as a modification and the case that angle difference is about 180°is excluded. Parameter design of proposed method is presented. A design of anti-vibration part is presented in the paper. Simulation testifies that the proposed method has great advantage over the constant frequency method. Also, this paper considers the application in real physical system and will be more adaptive to the real physical system.