This paper presents a high-security and large-capacity optical encryption scheme based on perfect high-dimensional Poincaré beams (HDPBs) generated through cascaded metasurfaces. The authors leverage the multi-channel phase modulation capability of chiral metasurfaces to expand the key and encoding spaces, enhancing the security and information capacity of optical encryption systems. By cascading two arrayed metasurfaces, the system can independently engineer more beam properties, leading to an expanded key space and encoding space. The encryption process involves encoding information into five independent parameters of HDPBs, including ellipticities, polarization orders, and azimuth angles. The decryption process requires precise alignment of the metasurfaces to retrieve the encoded information, making the system highly secure. The work demonstrates a promising strategy for advanced optical encryption systems with high security levels and large information capacities, potentially facilitating applications in optical communications and quantum information.This paper presents a high-security and large-capacity optical encryption scheme based on perfect high-dimensional Poincaré beams (HDPBs) generated through cascaded metasurfaces. The authors leverage the multi-channel phase modulation capability of chiral metasurfaces to expand the key and encoding spaces, enhancing the security and information capacity of optical encryption systems. By cascading two arrayed metasurfaces, the system can independently engineer more beam properties, leading to an expanded key space and encoding space. The encryption process involves encoding information into five independent parameters of HDPBs, including ellipticities, polarization orders, and azimuth angles. The decryption process requires precise alignment of the metasurfaces to retrieve the encoded information, making the system highly secure. The work demonstrates a promising strategy for advanced optical encryption systems with high security levels and large information capacities, potentially facilitating applications in optical communications and quantum information.