The present invention belongs to the civil engineering in-situ test technology field, and relates to a nonmetal anti-floating anchor multi-interface shear stress combination test method. The method performs synchronization real-time measurement of axial forces and shear stresses of a nonmetal anti-floating anchor body, an anchorage body and an interface of a rock and the anchorage body, and employs a novel test device to obtain pull-out amounts of the rod body and the anchorage body to research an anti-floating anchor mechanical transmission mechanism and deformation characteristics. The nonmetal anti-floating anchor multi-interface shear stress combination test method is simple in technology, simple in structure, high in test precision, high in operationality and direct and accurate in numerical result, can obtain multi-interface shear stress of a nonmetal anti-floating anchor, and is high in applicability and feasibility.