Abstract: Using SCM to control astronomical telescope automatic tracking objects of celestial bodies could replace manual running work by key-press operation.It has the characteristics of small volume,low cost and portable.The theories of automatic tracing,first of all,is manual tracking,so as to capture the rules of object movement and note down the tracks,and based on it to calculate the moving steps of step control,and finally,by controlling the running of step control which drives astronomical telescope running to reach the goal of automatic tracking.