Abstract: The corrosion failure accidents of austenitic stainless steel equipment are of common occurrence. Detection of martensite by electromagnetic methods possessed sufficient theoretical basis. Existing nondestructive test methods can not meet the requirements for fast, accurate and independent measurement of martensite content. Either improving the existing methods or developing a new method is very necessary, which can be used to detect the content of martensite of austenite stainless steel during the manufacture and in service. The method can estimate corrosion tendency in advance, which is helpful to reduce the corrosion failure.