In order to obtain the dynamic model of feed system quickly and accurately, a fast identification method for feed system based on open motion controller was proposed. Firstly, the feed system was excited by constant speed signal plus white noise as the excitation signal to reduce the influence of nonlinear friction on the model identification accuracy; secondly, the input data and output position feedback data were read in real time by using the open motion controller; then the feed system identification model was constructed by using MATLAB identification toolbox; finally, the identification model was verified by the actual processing program. The results show that the method can be used to establish the identification model of the feed system quickly and accurately.By setting reasonable constant speed signal and excitation amplitude, the influence of lowspeed nonlinear friction on the identification results can be greatly reduced, so that the matching degree between the model output and the actual output can reach 9811%. The maximum error of the linear part of the identification model is within ±3 μm.