The invention discloses a method for identifying surrounding rock load on an outer surface of a three-dimensional TBM shield, and relates to the technical field of high-efficiency tunneling and safetycontrol of a deep tunnel shield type TBM. The method comprises: 1, installing a strain monitoring sensor on a preset measuring point on an inner surface of a TBM shield; 2, obtaining strain measureddata of the measuring point [epsilon]m; 3, establishing a finite element calculation model of the TBM shield; 4, obtaining a load identification parameter through partition of the shield outer surface; 5, through Newton iteration and Moore-Penrose generalized inverse solution, obtaining surrounding rock load on the outer surface of the shield; 6, performing integration on the load to obtain outersurface friction resistance of the shield. The method has high calculation precision and good visualization effect, and is suitable for identification of outer surface load of the TBM shield on site,and can provide guidance for safe construction of tunneling, early warning of a stuck machine, and accident handling.