In a control system for synchronous rotation of the cutter heads in a multi-cutter shield machine, the rotating cutter heads are so disposed in generally same planes that the dis­tance between the centers of the adjoining cutter heads is larger than the radius, and smaller than the diameter, of the cutter heads. The rotating cutter heads are driven indepen­dently of each other by the electric drive systems, respective­ly. Each of the electric drive systems consists of plural motors with a reduction gear, coupled to the respective rotat­ing cutter heads by means of a pinion and gear. The motor rotation is so controlled and the cutter heads are so syn­chronously rotated, that the angle of deviation between the cutter heads is within such an allowable range that the cutter heads will not interfere with each other even if there is any imbalance in excavating and rotating resistances between the cutter heads.