The journal and the shaft shoulder of large-scale spindle are usually worn for insufficient lubrication or the entering of dust. Then, the large-scale spindle is necessary to be immediately repaired. Based on the repairing feature of the large-scale spindle and the main problem of the traditional repairing method, a planetary grinding equipment was developed. The working principle and the structure characteristic of the planetary grinding equipment were analysed. Furthermore, the spindle of the large-scale fan rotor was repaired in situ using the planetary grinding equipment. It was found that the repaired spindle has good dimension precision and surface roughness. A feasible technology was provided for the repairing of the large-scale spindle in situ using this machining method.