The invention relates to a connecting device for the separate hoisting of large offshore platform modules, which comprises a main supporting device body and stabbing cone devices, the main supporting device body comprises main-axis structural beams, transverse stay bars are fixed between the two main-axis structural beams, and horizontal oblique stay bars are fixed in the rectangular frames formed between the transverse stay bars and the main-axis structural beams; main module uprights are fixed at the joints between the main-axis structural beams and the transverse stay bars, and a working deck is arranged at a middle position between the main module uprights; side oblique stay bars are arranged in the space formed between each main-axis structural beam and each two neighboring main module uprights, the ends of the side oblique stay bars, which are connected, are fixed on the main-axis structural beam, and the other ends of the side oblique stay bars are respectively fixed on the bottom of each main module upright; supporting legs are also arranged between the main-axis structural beams and the side oblique stay bars, and the stabbing cone devices are arranged on the top ends of the main module uprights and the supporting legs. The connecting device can be widely applied in the field of offshore oil and gas fields.