The invention provides an excavator, and relates to the field of excavating. The problem that an existing excavator is poor in work efficiency can be solved. The excavator comprises a vehicle body, acab, a movable arm and a rotation device, the cab is fixedly connected with the vehicle body, the rotation device comprises a motor, a transmission gear and a rotation support, the rotation support comprises an inner ring and an outer ring which are coaxially arranged and mutually rotatably matched, the inner ring is provided with an inner gear ring and is fixed to the vehicle body, the transmission gear is engaged with the inner gear ring, the motor is fixed to the outer ring, an output shaft of the motor is in transmission connection with the transmission gear, the movable arm is fixed to the outer ring, the movable arm is arranged on the vehicle body through the rotation device, only through rotation of the movable arm, the square throwing work can be carried out, and the rotation loadis reduced; and meanwhile, through the motor, the rotation support is driven to achieve movable arm rotation, the driving speed of the motor is high, the rotation speed is improved, and the deflectionefficiency and the work efficiency of the excavator can be wholly improved.