The utility model provides an angular contact ball bearing and a dental air pressure type mobile phone and aims to improve the sealing performance of the angular contact ball bearing applied to the dental air pressure type mobile phone. The angular contact ball bearing with high performance is characterized in that a shoulder formed on one axial side opposite to a raceway surface and an opening shoulder formed on the other axial side are arranged on any of the inner diameter surface of the outer ring and the outer diameter surface of the inner ring, and a pair of shoulders formed on the two axial sides of the clamped raceway surface are arranged on any of the inner diameter surface of the outer ring and the outer diameter surface of the inner ring； a sealing part which extends from the shoulders to the inner ring in the radial direction and is corresponding to the outer diameter surface of the inner ring is also arranged on the outer ring； the sealing part and the outer diameter surface of the inner ring form a labyrinth seal structure.
