A three-dimensional modeling method of a digital controlled lathe workpiece provided in the present invention comprises the following steps: 1. image acquisition; 2. image parameterization; 3. feature extraction; 4. linearity assumption; 5. fitting judgment; 6. complete coverage judgment; 7. image functionalization; and 8. three-dimensional drawing. According to the three-dimensional modeling method, steps such as image parameterization and fitting judgment are used to ensure that automatic digitization and functionalization of a real workpiece image can be well implemented, so as to provide a solid and strong digital model basis for future overall intellectualization.