Abstract: According to the problems of the spectrum analyzer expensive and with poor open source and portability, based on the ARM series of architecture A8 and popular mobile platform of Android OS recently, a piece of spectrum analysis software was designed in the smart phone through the FFT algorithm in order to real-time process the audio signal, and also the spectrum was real-time displayed through the mobile phone screen to realize the function of spectrum analyzerThis way is a kind of pioneering work which the Android OS is used in the field of industrial automation and control platformThe spectrum analyzer will satisfy the delay performance and actual requirement of seamless, and have good man-machine interface, and also meet practical requirements such as delays, performance and seamless which can provide good experimental material for the inquiry experiment of the embedded curriculum