As an artificial micro-structure that can flexibly control the light field at the sub-wavelength scale, metalens has received extensive attention in the field of optical imaging in recent years. In the design of the metalens imaging system, the metalens is usually designed only according to the focal length and working wavelength, without considering the imaging process, which often leads to poor imaging quality of the whole system. In order to improve the imaging quality, a joint optimization method is proposed to achieve high-resolution imaging based on metalens by incorporating the two processes of metalens design and image reconstruction algorithm into the design process of the imaging system. This method not only optimizes the parameters of the metalens to obtain a ideal point spread function, but also achieves high-quality image reconstruction up to 2 times the resolution of the input image.