From the design perspective of an optical multi-dimensional information acquired device with small scale, simplicity, and easy integration, we analyze the principle of polarization and phase control of metalens, and design a metalens which can simultaneously focus Si-based orthogonal circularly polarized light based on geometry and transmission phases. The working wavelength of this metalens is 800 nm. It can simultaneously obtain two orthogonal circularly polarized light intensities of a target. The similarity between x/y polarized light rectangular structures is used to simplify the design process and reduce the design time consumption. From design perspective, we select the elementary structure with small depth-width ratio and large scale tolerance to reduce the processing difficulty. The finite difference time-domain (FDTD) simulation tool is used to verify the device function of polarization splitting and focusing imaging. The focusing efficiency is 56.2% when the numerical aperture of this metalens is 0.45.