The invention discloses an anchoring method applicable to a large-tonnage (larger than 50 tones) FRP inhaul cable. The FRP inhaul cable is anchored with a clamping piece type anchorage device, a protection transition layer with the length no smaller than the length of an anchoring area of the clamping piece type anchorage device is formed at the anchoring end of the FRP inhaul cable, the protection transition layer and the FRP inhaul cable are integrated, and the clamping piece type anchorage device is anchored to the protection transition layer. After the FRP inhaul cable and the protecting layer are pressed into a whole, while the shearing strength of the FRP inhaul cable and a protecting layer interface is increased, the phenomenon that the FRP inhaul cable weak in transverse strength makes direct contact with load transmitting mediums large in rigidity in the anchoring area can be avoided, a stressed buffering layer is formed, and the FRP inhaul cable can be indirectly protected. The anchoring method used for anchoring the FRP inhaul cable has the advantages of facilitating construction and being high in anchoring efficiency and the like, long-term performance of an anchoring system can be guaranteed, the method can also be used for tensile tests on the FRP inhaul cable, samples can be prepared easily and conveniently, and compared with an adhesive type anchoring method, test errors caused by overlarge shearing deformation of resin can be avoided.