According to the position servo system working principle, fault phenomena and fault causes, the servo system maintenance work for a new generation of Zunyi Doppler weather radar is summarized as follows: (1) The orientation of the servo system in fault can be classified to five kinds of typical faults, and specific measures corresponding to maintenance are found out; (2) Position servo system has many components, distributed in many different places,thus repair work is difficult, the maintenance personnel have to master system composition and working principle, and then through graded judgment found out the fault location;(3) Oscilloscope and three-phase multimeter are mainly used in position servo system maintenance and inspection, thus technical personnel must be skilful in using; (4) From the occurrence of failure positions to see, faults are mainly concentrated in the position driving system, thus technical personnel have to master the azimuth drive principle, the inspection parameters of corresponding parts and the measured values, especially to remember some test waveforms.