The three ball pin type constant velocity universal joint is provided with a ball pin and a groove shell. The ball pin is provided with three evenly arranged ball rings along the circumference. Three grooves corresponding to the three ball rings are respectively arranged in the groove shell. The outer global surface of each ball ring is respectively movably pressed with the groove walls on both sides of the corresponding groove. Each groove wall is composed of a first arc-shaped wall and a second arc-shaped wall, and the curvature of the two arc-shaped walls is the same, There is a gap between the intersection of the two arc-shaped walls and the outer ring surface of the corresponding ball ring, which has the advantages of high bearing capacity, wear resistance and long service life; changing the single arc-shaped groove wall into double arc-shaped groove wall can increase the contact between the groove walls on both sides of the groove wall and the outer ring surface of the ball ring, improve the bearing capacity of the three ball pin type constant velocity universal joint, make the force between the ball ring and the groove more reasonable, and increase the wear resistance So as to improve the service life of the three ball pin constant velocity universal joint.