The present invention discloses a bridge three-dimensional model construction method based on the BIM. The method comprises the following steps: dividing objects of an whole structure of the bridge, and classifying the objects of the bridge in a normative manner; subdividing the bridge components into elements and primitives, parameterizing the elements and primitives, and formulating a parameter table corresponding to the geometric dimensions; carrying out assembly and positioning on the three-dimensional model of the bridge components, determining and defining element control points and relative spatial position relationships, assembling the elements into components, storing the components into an component template library, and establishing component control points; extracting three-dimensional route information of the project, and determining stake marks and the design elevation of the route; and assembling the component three-dimensional model, based on the route information, using positioning parameters to determine the location of the component model, and calling the type method, so that parametric assembly can be automatically carried out between components. According to the method disclosed by the present invention, by optimizing the bridge model, parameterization and standardization of the bridge components are realized, the modeling time is shortened, and the design efficiency and quality are improved.