Aiming at the problem of mastering working status of turnout switch machine accurately, predicting the tendency of turnout fault timely, realize “repairing for status” really, brings forward one kind of the method of association analysis which is based on action power curve of turnout switch machine. Taking typical action power curves of S700K alternating turnout switch machine as example, this paper discussed the method from 2 aspects which were distribution of type of action power curve of turnout switch machine and association analysis of turnout fault firstly, and described extracting, data condensation and association analysis of the action power curve of turnout switch machine deeply. Result is indicated, this method is able to guide the association analysis of turnout fault successfully, can rise quality of actual check and repair, lessening design risk, cut down cost of repair thereby, and providing the data sustain of “repairing for status”. The method is result to be project feasible, it had fine application extension value also.