Abstract: The elemental analyzer-isotope-ratio mass spectrometer(EA-IRMS)is sensitive,rapid,efficient and convenient properties,which is widely used in isotope natural abundance analysis and trace analysis.The scientific management and proper use and maintenance of the elemental analyzer-stable isotope ratio mass spectrometer is the prerequisite and foundation for boating good test data and prolonging the service life of the instrument.This article describes the working principle and operation flow of the elemental analyzer-stable isotope ratio mass spectrometer,and proposes the countermeasures for the problems that arise during the use.In addition,routing maintenance and precautions during the use of the elemental analyzer-isotope proportional mass spectrometer are described.