As the big circle plane between 5000 ~ 20000 mm exist the problem that the precision is difficult to ensure during the machining process. Based on the analysis and study of the key problems,the method of high precision electronic sensor was used to collect the dates and computer software was used to analyze and calculate,then a set of test scheme was proposed which was based on angle senor and tilt angle senor combine with servo motor movement control and also treated Labviewas it's core. Finally,a set of h...