Based on the current market can not meet the rapid development of preschool children ages in the psychological and physiological characteristics,it introduced in the design of children furniture.It discussed the necessity for ductility design of children's furniture,on the basis of this;it purposed three innovations of research methodology in its functional extensibility,structural extensibility and material extensibility to solving the problems,and finally help designer create the growth furniture to accompany children grow up in the restriction condition.