The invention discloses a three-dimensional CAD model similarity retrieval system and method based on image recognition. The system comprises a database, a feature recognition module, a similarity calculation module, a similarity retrieval module and a result display module. A three-dimensional CAD model and a target three-dimensional CAD model are stored in the database. The feature recognition module traverses all the three-dimensional CAD models in the database, recognizes geometrical features of each three-dimensional CAD model in at least three view directions, takes the geometrical features as view feature values, and stores the view feature values and the corresponding three-dimensional CAD models into the database in an associated manner. The similarity calculation module is used for calculating the similarity of any two three-dimensional CAD models in the database according to the view feature values of the three-dimensional CAD models, and storing all similarity results obtained by calculation in the database. The similarity retrieval module is used for sorting similarity results related to the target three-dimensional CAD model in the database, and the result display module is used for displaying the three-dimensional CAD model similar to the target three-dimensional CAD model and the corresponding similarity according to the similarity sequence obtained by the similarity retrieval module.