This paper studied the error averaging effect of the linear guide pair based on finite element simulation method and proposed an assembly process to improve the accuracy of the kinematic subassembly. Firstly, a finite element modeling of a linear rolling guide pair is developed. The error transfer relationship between guide and kinematic subassembly is researched by simulating different combinations of guide errors. Secondly, the linear rolling guide pair experimental bench is built to experimentally verify, and the experimental results coincided with simulation analysis. Finally, in order to improve the accuracy of the kinematic parts, an assembly process is proposed.