In order to solve the problems of comprehensive flexibility of robot arm, and expand the application field of service robot and improve the safety, a one-dimensional two-way flexible bending joint is developed by using the self-developed pneumatic artificial muscle. The relevant theoretical model is established and the relevant experimental analysis is carried out. The experimental results show that the bending joint can realize one-dimensional two-way bending motion and the bending angle of the joint can be controlled by adjusting the gas pressure; when the air pressure difference between the two sides of the leaf spring is 0.22Mpa, the maximum bending angle of the joint reaches 74.12 degrees; the forward and reverse bending of the joint are consistent, and the joint bending curve is similar to the arc.