The invention provides a grid connection/disconnection seamless switching method for a micro-grid converter. The method comprises the steps that (1) load voltage Uload of each power electronic device in the micro-grid converter at the moment of switch cycle is detected in real time; (2) according to the absolute value |deltaU| of the difference value between the load voltage Uload and the real-time voltage expectations U of a grid, the grid connection/disconnection working mode of the micro-grid converter is switched, wherein the micro-grid converter comprises a three-phase full-bridge converter body and a controller; the controller controls an AC thyristor SCR to be disconnected according to the comparison result between |deltaU| and a voltage different threshold deltaUlimit, so that a micro-grid is switched from the grid connection mode to the grid disconnection mode. Compared with the prior art, according to the grid connection/disconnection seamless switching method for the micro-grid converter, grid abnormality can be quickly detected, the grid and a load can be disconnected, and the stability of the voltage of the local important load can be maintained.