Travel error is an important parameter to evaluate the accuracy of planetary roller screw pair, but there are a few studies on the influencing factors and modeling of travel error. Therefore, firstly, the influencing factors of travel error of planetary roller screw pair are analyzed, including machining error, installation error and deformation error. Then, based on the error conversion, the travel error model is established and the errors are measured. Finally, the travel errors of four planetary roller screw pairs and the travel errors of planetary roller screw pairs under six different load conditions were measured with the travel error test bench. The test results show that the machining processing level and installation accuracy have a great influence on the travel error index, and the travel error of the screw pair increases with the increase of the load, which indicates that the deformation error caused by the increase of the load has a great influence on the travel error. The relative error between the test value of the screw travel error and the calculated value of the model is 1. 62% ~ 4. 37% , and the relative error of the screw pair is 1. 81% ~ 6. 53% . The effectiveness of the model is verified, the study can provide a reference for the transmission accuracy analysis of the feed system.