As the key component of machining center, the reliability level of feed shaft directly affects the machining accuracy. The quick testing method of the reliability test was put forward. The design scheme of the feed shaft reliability test device was completed. Through building the reliability test device for the feed shaft，related loading test for the feed shaft reliability was carried out. And combining the test results with other machining center reliability test results, using corresponding data analysis software, the reliability index of machine tools were assessed, defects in processing center feed system design, manufacturing and assembly etc were exposed, which guided reliability design of feed shaft unit, to ensure the reliability growth of feed shaft in the design and use process.