The present invention relates to a multi-blade electric rotary razor which comprises a razor blade cartridge turned by a motor, and at least one pair of razor blade assemblies disposed at an equal-angle distance at the razor blade cartridge along a direction in which the razor blade cartridge rotates, at least one pair of razor blades (hereinafter referred to as first razor blades) being arranged in an overlapping manner at a predetermined distance at the razor blade assembly along a radius direction of the razor blade cartridge. The electric rotary razor of the present invention has a structure of a wet shaver where multiple razor blades are arranged, and uses the motor to turn the razor blade cartridge during shaving for user convenience and thorough shaving. The multi-blade razor blade assembly alleviates a dermal stimulation, minimizes a possibility of a scar, and does not require shaving cream, making shaving convenient and unhindered by time and space.