Abstract: The current research on chiral honeycomb structures not only focuses on the materials used for the structure itself but also emphasizes improving mechanical performance by altering the internal topological arrangements of the units. Most existing chiral honeycomb structures feature rigid central nodes that increase both structural stiffness and overall weight. Addressing this situation, this paper proposed a novel tetra-chiral cell structure characterized by easy deformability and good extensibility. Theoretical deductions of beam structure mechanics using energy methods were presented, along with numerical validations using finite element analysis. Through parameter analysis, the mechanical performance of this structure was discussed. Results indicate that this structure, with a negative Poisson's ratio, demonstrates excellent mechanical properties. It exhibits an equivalent elastic modulus as low as 10⁻⁶ and a large range of shear coupling coefficients as low as −5.5. The equivalent elastic modulus is only 10% of that of a V-beam structure, and the equivalent shear modulus is lower by two orders of magnitude compared to an ATCS structure. The range of mechanical performance adjustment is also approximately 1.5 to 2 times that of the ATCS structure. As a new type of chiral structure, its lower equivalent elastic modulus and wider range of shear coupling coefficients present significant potential applications in aerospace, maritime, medical, and other fields.