The invention relates to a motor assembly machine capable of accurate blanking. A lower bracket is provided with a motor shell material receiving and positioning device; the back side of the motor shell positioning device is matched with a motor shell conveying device, the left and right sides of the motor shell positioning device are matched with a motor shaft conveying slot, and the upper part of the motor shell positioning device is matched with a blanking device; the left side of the motor shaft conveying slot is matched with an ejecting device; the motor shell positioning device comprisestwo material receiving and positioning baffle plates which are arranged on the lower bracket; gaps are formed in the parts, matched with the motor shaft conveying slot, of the two material receivingand positioning baffle plates; the material receiving and positioning baffle plates are provided with a material receiving and positioning rotating shaft and a material receiving and positioning motor; the material receiving and positioning rotating shaft is sleeved with a material receiving and positioning rotary cylinder; and material receiving and partitioning boards are uniformly arranged on the outer side of the material receiving and positioning rotary cylinder along the annular direction. According to the motor assembly machine, the rotatable motor shell material receiving and positioning device is matched with the motor shell conveying device and the motor shaft conveying slot to realize continuous feeding of a motor shell; meanwhile, the motor shell can be inaccurately butt jointwith the motor shaft; and accurate blanking can be realized in conjunction with blanking device.