The invention provides a method which utilizes metal transition super-plasticity to carry out spring sizing, which relates to a method for sizing the shape of a spring and solves the problem that the size is not qualified due to the distortion of the spring. The method utilizes tools and technique equipment to apply force continuously on the parts size of which is out-of-tolerance so as to fix the size to the tolerance limits; the spring and the tools are put into a furnace to carry out heat treatment, during the heat treatment, phase transition happens to the spring and the spring utilizes the super-plasticity that the spring has during the phase transition to carry out plastic deformation; the tools are removed after the spring and the tools are taken out of the furnace. The method utilizes phase transition superplasticity during normal heat treatment to carry out sizing, needs small strain and no other heat treatment procedures and can fulfill the purpose of sizing during normal heat treatment process.