Construction method of bearing platform at soft and hard geological junction of mud flat area

The invention relates to a construction method of a bearing platform at a soft and hard geological junction of a mud flat area, which comprises the following steps: pouring a layer of reinforced concrete bottom plate connected with a pile foundation steel casing into a whole at the bottom of a foundation pit, arranging a circle of second embedded parts on the periphery of the upper end of the reinforced concrete bottom plate, and fixing the bottom of a steel cofferdam with the second embedded parts, the installation stability of the steel cofferdam is improved, and the problems that steel sheet piles cannot be driven into the hard area side, the bearing capacity of the soft side is low, and the steel cofferdam cannot be positioned are solved. Besides, a plurality of first embedded parts are evenly distributed on the side wall of the steel casing, and after the first concrete bottom plate layer and the second concrete bottom plate layer are poured, the first embedded parts and the corresponding calf legs are e