The invention discloses a guiding and positioning mounting method for an oceaneering module. The method comprises the following steps: 1. guiding components (1 and 2) are made; 2. a plurality of the guiding components(1 and 2) are vertically arranged on a pre-assembled platform(6) at intervals; 3. by utilizing panels of the guiding components, the oceaneering module waiting for folding is guided, the positioning mounting of support legs of the oceaneering module is guided, and the oceaneering module is fixed by welding; and finally, redundant guiding components(1 and 2) are cut. By the guiding and positioning mounting method, steel components of which the upper part is cut to be inclined by a steel plate are mounted on the mounted position of the large-sized module, and welded with the existed structure, the support legs of the large-sized module can be conveniently inserted in the guiding device; because the guiding components are easily processed and conveniently used, the accuracy of the folding, mounting and positioning of the large-sized module is greatly improved.