The invention discloses a large-size shaft-type part high-precision measuring device and method. The large-size shaft-type part high-precision measuring device mainly comprises a support platform, a sensor group, a guide rail, a revolving platform and a tip tail seat. The guide rail is arranged on the support platform. The guide rail is in sliding connection with a guide rail slide block. An installation rack is vertically installed on the guide rail slide block. The sensor group is fixed on the installation rack. A support seat and a free guide rail are respectively arranged on two ends of a working surface of the support platform. The tip tail seat is installed on the free guide rail. The revolving platform is arranged on the support seat. The revolving platform and the tip tail seat clamp and support a shaft-type part to be detected. The large-size shaft-type part high-precision measuring device and method solve the problems of an existing measuring device that manual measurement or visual measurement is adopted for large-size shaft-type part detection, the measurement is failed or the stability is poor, the efficiency is low and the precision is low. The shaft-type part high-precision measuring device provided by the invention is capable of measuring the shaft-type parts different in length, the measuring precision is relatively high, the stability is good, and the efficiency is high.