Research conclusions:(1)On this basis，a universal algorithm for chord deflection offset was established which is based on short chord MCO data. The result of computer simulation has verified the accuracy of the universal algorithm.(2)By means of frequency characteristics and error characteristics analysis，this paper argued that:contrast with bias-chord offset differential method，MCO method has some characteristics in the same chord length，e. g. zero phase shifting， richness of irregularities information，location convenience and characterization of dynamic properties. Not only that，the MCO method is able to extract the information of long wave irregularities with extended algorithm.(3)The universal algorithm established in this paper should provide a new method for the measurement of chord deflection offset in HSR survey.