The invention discloses a complicated product model construction method based on a surface feature, and the method comprises the following steps: firstly, carrying out instantiation on the surface feature by setting characteristic parameter values; secondly, locating the surface feature of the instantiation at a surface model; then automatically generating a transition surface feature so that the surface feature is smoothly combined with an attachment surface; and finally establishing a surface feature model by putting up building blocks till the construction of a product model is finished. According to the method, the surface feature is effectively used as a design unit, like a regular feature model system, so that the surface feature with specific function semantics is conveniently used for establishing the feature model. The method is applied in CAD (Computer-Aided Design) model construction so that a product can have smooth appearance and stronger function; and therefore, the requirement of the user is better satisfied, the product competitiveness is efficiently promoted, and the design efficiency is improved.