Abstract: Disclosed is a least square-based mechanical arm control method for robot experimental teaching, which includes: acquiring an image of a target object, and calculating position coordinates of the target object by using the image of the target object; setting a pickup distance, selecting a plurality of first sample points and second sample points according to a position target, and controlling, by using a swing steering engine, a claw to sequentially move along a first trajectory and a second trajectory; reading a duty ratio S of PWM signals in the swing steering engine, and calculating a value of Di=S/P; fitting xi based on a least square method to obtain a fitted equation; adjusting the pickup distance, and correspondingly setting the duty ratio of PWM signals in the swing steering engine according to the fitted data and controlling the claw to sequentially move along the first trajectory and the second trajectory.