Abstract: According to the problems of the application in the practical engineering of the U-steel support such as passive support,supporting resistance offered hy steresis,nonuniform load stressed on the supporting structure,this paper designed,a U-steel support and surrounding rock stress coupling device,and its structure type, mechanizm and operating characteristics were researched by experiment. The results showed that the coupling device enabled the surrounding rock and support struct ure form a common mechanical bearing system,it could provide 20 ~ 50 kN setting load and uniform surrounding rock pressure, which greatly increased the bearing cap acity of U-steel support,and it had a certain yield and damping effect. Different support requirements of coupling device could be designed while changing its structural r igidity and size.