The YZWⅡ type external electric drum is a new type of driving unit for various belt conveyors, bucket elevators, winches, etc. It serves as a conveyor driving device that lies between the traditional open transmission of motor-reducer-drive shaft and the common electric drum drive. It boasts good external heat dissipation for the motor and ease of maintenance or replacement for the motor. In terms of space occupancy and manufacturing materials, it reduces about one-third compared to open transmission, but is about one-third larger than the common electric drum.