Provided is a molding method of a sealing cover, realized by setting up a sealing cover mold, the mold includes a cavity and a core group arranged in the cavity, including setting up a first core and a second core, the mold opening direction of the first core and the second core are not parallel. The present application does not need a process hole to perform the injection molding of the sealing cover with a fastening structure, whose sealing is also better.