With the continuous improvement of imaging performance requirements, the design of imaging systems has become increasingly complex, making it more difficult and expensive to manufacture and test. To overcome these problems, a simplified design framework for imaging systems based on aberration characteristics of optical-digital joint optimization was built in this paper. Specifically, an improved total variation regularization restoration algorithm was proposed, and the difficulty of correction for different monochromatic aberrations was evaluated. With this evaluation, the proposed algorithm was combined with the traditional optical design method to jointly correct the aberration and simplify the optical system by relaxing the requirements for optical structures and surface shapes under the guarantee of the imaging performance. To demonstrate the feasibility and efficiency of the method, three design examples are provided, where the structure similarity index measure of the simulation imaging results is on the same level as that of the initial system, with a maximum error not exceeding 0.04. The simulation results demonstrate that our design method can effectively simplify the optical structure of imaging systems while maintaining high performance.