Provided is a mounting method of special-shaped large-span net rack high-altitude positioning blocks. By means of the stability of the geometric invariant system of the triangular pyramid or quadrangular pyramid of a net rack or a net shell, a main bearing belt of certain rigidity is chosen, the main bearing belt is used for mounting and folding first, the net rack or net shell with the large coverage area is divided into multiple operation areas, and then regional paralleling and symmetrical mounting are conducted. A main bearing support is mounted first, specifically, the mounting process comprises the following steps of (1) main bearing belt determining, (2) construction preparation, (3) measuring repeated leveling, (4) scaffold erecting, (5) mounting preparation, (6) support mounting, (7) on-site measuring, (8) main bearing belt mounting and adjustment, (9) main bearing belt folding and (10) regional component splicing. According to the mounting method, the construction process is simple, the construction sequence is reasonable, site conditions and self structure features are fully utilized, construction is novel, unique, safe and reliable, mounting precision can be guaranteed, the mounting stress of components is reduced, the mounting quality is guaranteed, the construction period can be greatly shortened, and the economic efficiency is appreciable.