The invention discloses an injection moulding method of a digit wheel and a mould thereof. The method comprises the following steps: closing and molding a font front mould and a rear mould, opening the font front mould and the rear mould, rotating a rotating disc of a double-colored injection machine, rotating the rear mould to a second forming position, closing and molding the rear mould and a wheel body front mould, opening the wheel body front mould and the rear mould, pushing a product out, rotating the rear mould to a first forming position, and the like. The digit wheel mould comprises the front mould and the rear mould, wherein the front mould is a font core front mould, and the rear mould is a font core rear mould. By adopting the digit wheel mould, plastic digits on a digital display measuring meter can not be printed on the surface of the product by a rotary printing process any more, but the model product produced by directly adopting the digit wheel mould, therefore, not only the production process for producing the digit display measuring meter is reduced, the cost is saved, but also any pollution to the environment can not be generated, and the mould is very economicand practical.