In ultra-long-distance rock micro-shield pipe jacking, pipe wall friction is a key factor in determining the size of the jacking force and the arrangement of the intermediate jacking station, and the selection of a good bentonite mud is a key factor in controlling the pipe wall friction. In order to give full play to the polymer bentonite mud in the pipe jacking construction process of lubrication and support, this paper to Chongqing Guanjingkou Water Conservancy Hub project as a basis, through orthogonal tests and indoor straight shear test method on the basis of different types of bentonite mud ratio optimization, based on the performance parameters of the slurry, as well as the friction reduction mechanism to derive the optimal type of mud and its ratio. The results show that: sodium bentonite mud is the optimal type of mud, the ratio of bentonite to water is 14%, guar gum is 0.20%, soda ash is 0.4%, CMC is 0.4%, PAM is 0.10%, and its friction reduction effect is obvious, it can make the friction coefficient between concrete and gray rock reduced by 35%, which makes the friction between the pipe and the rock greatly reduced in the process of pipe jacking in the rock.