Abstract: This paper introduces the steps and technical requirements for the fluorescent magnetic particle testing of steam turbine rotor blade by using the method of coil and magnetic yoke.Suitable technological parameters for the test were identified through experiment and the actual testing of steam turbine rotor blade was performed,and at the same time a contrast experiment was made with penetration detection.The test showed that the fluorescent magnetic particle detection method could effectively detect smaller defects in the blade end,root and surface of the leaf body with high sensitivity and high reliability for in-service inspection of blade and other irregular shape of products.