A main technical feature of a method for molding and forming a flip-flop and a mold thereof provided by the invention is that when a polymer raw material is filled into a mold chamber space of the mold, the filled raw material is preferentially flowed in a direction of a strap area space used to mold a V-shaped strap portion of the flip-flop to ensure that the slender V-shaped strap portion of the flip-flop can be integrally formed.