Abstract: econdary electron emission characteristics have a significant impact on vacuum devices in many fields, and accurate measurement of secondary electron yield(SEY) is critical. In this paper, we present a method for measuring SEY based on scanning electron microscopy. We take advantage of the high stability of the electron beam current and the wide range of tunable electron energy, and add a specimen stage with Faraday cup to measure the SEY of smooth Ag by changing the scanning speed, magnification and focus state. The result shows that the secondary electron yield of smooth Ag is not affected by the electron microscopy parameters and is in accordance with the measurement result of the reference. This method is an important reference for the study of the secondary electron emission characteristics of the material over a wide incident electron energy range.