The calibration method based on general imaging model is proposed by using the grating projection three-dimensional measuring technology for three-dimensional reconstruction of small objects. Different poses of the calibration target rotating around the fixed axis are utilized to calibration and optimization. The proposed calibration method solves the problems of general imaging model variables and does not need to use precision displacement device. In the meanwhile, a self-convolution blind deblurring method is used to solve the defocus caused by small depth of field of the telecentric lens, and improves the calibration accuracy of camera. The feasibility and veracity of the proposed method are demonstrated with experiments of calibration and three-dimensional reconstruction. The measurement accuracy achieves 6 μm when the camera field of view is 23.7 mm×17.78 mm.