In view of the problems such as the difficulty in detecting the change of body height in the deterioration process of air spring in rail transit vehicle,the low accuracy of pressure measurement,and the lack of intelligent early warning function,an intelligent monitoring system for air spring in rail transit vehicle was designed.The structure,hardware,software and working process of this monitoring system were introduced,and the technological innovation point was analyzed.This monitoring system applies intelligent sensing technology,data dump technology and intelligent early warning technology,which can accurately measure the change of internal clearance and the change of internal pressure value of air spring,realize intelligent early warning and maintenance,and thus improve maintenance efficiency and save maintenance cost.