Structural design method of expandable ocean platform with functional modules

The invention relates to a structural design method of an expandable ocean platform containing a functional module, which comprises the following steps of: aiming at a plurality of existing central processing platforms in the Bohai Sea, carrying out regression analysis on in-service central platforms according to different oil-water processing capacities, equipment quantity and total area to form a four-grade standardized central processing platform; selecting general overall arrangement and equipment types in the four-gear central processing platform to form a reference platform; n functional modules are formed on different parts in the four-gear central processing platform, and finally the combination mode of the reference platform and the N functional modules is achieved so as to meet the development requirements of oil and gas fields. Wherein N is the number of the function modules. According to the invention, a development thought of ''a reference platform + N functional modules'' is adopted, and the num