The invention discloses a control method for smooth and synchronous grid connection of a mircrogrid. Automatic compensation is conducted in the inconformity situation that mutual inductors on the two sides of the mircrogrid are inconsistent through automatic amplitude compensation and automatic phase angle compensation; the closing time length of a circuit breaker is compensated for through lead time compensation; power quality detection is adopted, and when the power quality is unqualified, synchronous grid connection is not allowed; synchronous grid connection detection and adjustment of single phase/three-phase self-adaption are adopted to conduct automatic detection and judgment on three-phase imbalance degree, when three-phase voltage is imbalanced, the three-phase synchronous grid connection detection and adjustment process is conducted, and when the three-phase voltage is balanced, single phase synchronous grid connection detection and adjustment process is conducted. By means of the method, smooth and synchronous grid connection of the microgrid at the optimal angle is achieved, so that impact of the grid connection on a power grid system and a microgrid power equipment is the smallest, the service life of the power equipment is prolonged, power grid stability is improved, and the control method has good application prospects.