Based on Visual Basic (VB) developed software of a system for the guide rail accuracy predicting, which mainly contains four modules: engineering data management, finite element analysis (FEA), accuracy retentivity prediction and accuracy retentivity test. Engineering data management was mainly contained of a material base, a surface morphology database of the guide rail, and had the functions of experimental database storage, query and management, and etc. Through secondary development, the effective combination of sliding guide rail accuracy retentivity predicting system and ABAQUS FEA software was realized. By developing the guide accuracy retentivity theoretical analysis module, the straightness analysis was realized and draw an attenuation graph of the guide rail straightness was drawn under intruction of the theory. Finally, a guide accuracy retentivity analysis module was developed. Under the real working condition experiment, after analyzing the experimental data, the keeping time of guide rail accuracy is obtained, and an attenuation graph and the output text file is drawn.