The present invention directs an elastic hinge for quick-assembly leg including: a double-tooth of hinge, a screw, a spring core assembly and a leg; wherein the spring core assembly includes a elastic buckle, a single-tooth frame which is inserted in cavity of the elastic buckle, a core pin sleeved in a cavity of the elastic buckle which is formed after the single-tooth is assembled into the elastic buckle, and a spring sleeved on the core pin; the elastic buckle is provided with a fastening part and a leg is formed with locking part to engaged with the fastening part, and the removable part of the leg and the elastic hinge are assembled together.