The new waterproof material polypropylene was used as the inner waterproof layer of the underground granary structure. The connection performance of the waterproof layer and the inner wall of the grain silo is important to the waterproof system in underground granary structure. The technical scheme of connecting the waterproof layer with the underground grain silo wall by a new connector(threaded polypropylene rod) was described. The bonding performance between threaded polypropylene rod and concrete was investigated and calculated.The mathematical expression of bond strength, relative slip and length of the threaded polypropylene rod and concrete was given. The results show that according to the experimental research and mathematical expression, it is possible to determine the bond strength, relative slip and limited anchor length, which provides a theoretical basis for the further design of plastic concrete components.