Abstract: A horse buckle includes a buckle ring seat; a prong movably coupled to the buckle ring seat; an elastic unit arranged between the buckle ring seat and the prong and including an elastic element having two end respectively fixed to the buckle ring seat and the prong, a barrel fit outside the elastic element, and a pin mounted to one side of the buckle ring seat and movably coupled to the prong; and a support unit movably mounted to an end the buckle ring seat. As such, the buckle ring seat is coupled to a girth for use and receives a fastening strap to extend through the buckle ring seat and a restoration spring force of an elastic element makes a prong quickly seated in a positioning hole of the fastening strap.