The invention aims at providing a method for constructing or reconstructing an assembled platform and a special prefabricated module group. According to the method for constructing or reconstructing the assembled platform, the efficiency of the platform constructing or reconstructing project can be comprehensively enhanced, the platform constructing or reconstructing project quality can be comprehensively improved, the construction is simple and flexible, manpower and material resources are saved, the influences on running and transportation are small, the method is safe and time-saving, and the potential safety hazard in the later period is reduced. The method for constructing or reconstructing the assembled platform comprises the specific construction steps of 1, preparing a prefabricated module group with a reinforced concrete structure; 2, mounting the prefabricated module group to a designated position by using a hoisting appliance; treating a foundation of a new platform and filling anti-freezing sand first, and then mounting prefabricated modules after pouring a concrete strip-shaped foundation; 3, binding reinforcing meshes on the prefabricated modules and pouring a concrete cushion; 4, comprehensively laying pipelines; and 5, after the concrete cushion reaches the strength, continuing to lay a slope making layer, a leveling layer and a sand cushion; and laying a platform cap-beam, a safety line, blind bricks and pavement bricks to finish the construction.