The invention relates to a moulding method of a soft contact lens. The preparation method of the mould comprises the following steps: 1) designing and processing a metal core, 2) performing injection molding of the mould; 3) curing and forming a lens; 4) performing hydration of the lens; and 5) packaging the lens. The lens mould of the invention can be used to satisfy the forming of the soft contact lens and used as the hydration container of a semi-finished lens and as the packaging container of a finished lens too. The invention also has the advantages of stable injection, simple hydration operation and low injection low.