The machine tool accuracy is comprehensively affected by geometric, thermal, and cutting force-induced errors. A key step in accuracy design and error compensation is error origins analysis. The object of this study is a MCH63 Precision Horizontal Machining Center. Based on the volumetric error model and using the measurement of error origins, the effects of geometric, thermal, and cutting force-induced errors on the volumetric error components are compared. The results can be used to theoretically direct the accuracy design of different error sources and provide experimental data support for error compensation.