Overview: Metasurface is a new kind of artificial two-dimensional material. Its working principle is to flexibly control the amplitude, phase and polarization of the incident electromagnetic wave by using the local interaction between the subwavelength scale unit cell and electromagnetic wave. Compared with traditional optical devices, devices based on metasurfaces have the advantages of compact structure, diverse functions, and easy integration. Therefore, metasurface has become a research hotspot in optics and photonics. At present, the electromagnetic manipulation devices based on the metasurfaces have achieved many novel functionalities, such as perfect absorption, anomalous deflection, focused imaging, electromagnetic cloak, and high efficiency holography. However, there are still some key problems to be solved in this field such as low working efficiency and narrow bandwidth. In recent years, the emergence of catenary electromagnetics provides new ideas and methods to solve these problems. In fact, catenary was first used in engineering and architecture to describe the shape of a soft rope suspended under the uniform gravitational force between two horizontal points. The use of catenary equations to solve problems in the field of electromagnetism has only recently been discovered by researchers. In this paper, we proposed a metasurface absorber based on a twisted catenary structure in the near-infrared band. The local electric field enhancement effect of the structure is different when the incident electromagnetic wave is with opposite spins, which can achieve efficient chiral selective absorption. The simulation results show that the circular dichroism is larger than 78% at the working wavelength. At the same time, the designed structure also has good angular stability, and can still get larger than 60% circular dichroism absorption in the case of oblique incidence at different azimuth angles. Besides, a possible method of information encryption using this kind of structure is proposed. Different information can be read by controlling the handedness of incident electromagnetic wave. This work further enriches the content of catenary electromagnetics, and has certain research value in the fields of chiral imaging and chiral sensing.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.