Polarization is an efficient approach for optical information encryption. However, most polarization encryption devices employed a single channel or double channels. In this work, an optical information encryption device based on double layer C-ring metasurface in terahertz band is proposed. Three channels are exploited to encrypt information. Three different images can be achieved via tuning the polarization of illuminating and detection wave. The theoretical analysis based on Jones matrix is given to show the validity of the proposed approach. Experiment is carried out in the terahertz band. The result also demonstrated that the designed device can performed the desired functions well. It is expected that this approach can be applied in compact large-capacity information storage, color holographic displays, optical encryption, as well as multi-function imaging.