Different railway line cases with different object functions will result in different or completely adverse optimal nose shape.In this paper, a method for high-speed nose shape design was proposed to provide a suitable nose shape under multi-line cases.The method with emphasis on reduction of computational costs combines mentamodel and numerical optimization techniques.An exemplary nose shapes under open air and passing tunnel line cases were designed by this technique.The comparison between the current CRH2 and those optimal nose shapes demonstrated the capabilities of the method.