Abstract: As a kind of artificial two-dimensional material, metasurfaces have drawn wide attentions in recent years due to their ultra-thin profile and flexible electromagnetic manipulation capability. Therefore, how to further improve the working efficiency of metasurface devices has become a hotspot in this field. Catenary electromagnetics as an emerging metasurface design principle provides new ideas and methods for designing efficient metasurfaces. Here, we proposed a metasurface absorber based on twisted catenary structure that can achieve efficient spin-selective absorption. The simulated results indicate that the perfect absorption can be achieved for left-handed circularly polarized incidence at the working wavelength, while the absorption for right-handed circularly polarized incidence is below 22%. The corresponding circular dichroism is larger than 78%. Besides, the physical mechanism for the chiral absorption is analyzed and a promising application for information encryption is also discussed. This work may find potential applications in chiral imaging and chiral sensing.