The invention discloses a connecting structure of a micro planetary gear reduction motor. The connecting structure comprises a micro planetary gearbox, a motor output shaft which drives a motor, and a sun gear which is connected with the motor output shaft; a connecting tooth sleeve sleeves an outer ring of the motor output shaft and is in transmission connection with the outer ring of the motor output shaft; the outer end of the connecting tooth sleeve protrudes from the outer end surface of the motor output shaft; a first inner tooth ring is arranged at an inner ring of the protruded part of the outer end of the connecting tooth sleeve; one end of the sun gear is arranged in the connecting tooth sleeve by sleeving, and first outer teeth which are composed of incomplete teeth are arranged in the outer ring of the end, wherein the first outer teeth are engaged with the first inner tooth ring; the motor output shaft is characterized in that the gear wheel is driven by the connecting tooth sleeve to rotate. According to the connecting structure, the sun gear and the motor output shaft are separable, so that the center distance from the sun gear to the motor output shaft can be adjusted properly, so as to realize the uniform distribution of the load, and as a result, the transmission performance is improved.