Banhu art and Erhu art represent two major categories of Chinese bow string musical instruments, namely, bow string musical instruments with wooden board surface vibration and bow string musical instruments with skin film surface vibration. Their development leads the development of Chinese bow string musical instruments. This paper is divided into four chapters, using the methods of literature review and comparative research to discuss the differences between them and seek the problems existing in their development. Finally, a reasonable development method and direction are deduced according to the problem.