To improve the dimension accuracy, an experimental investigation has been conducted to determine the optimum build parameters of integral stereolithography (SL) system with Taguchi method. The build parameters include shrinkage compensation factor of resin (factor A), liquid surface waiting time (factor B), exposure time (factor C) and light intensity (factor D). It was found that factor A, factor B, factor D and the interaction between factor A and factor D significantly affect the dimension accuracy, and the interaction between factor A and factor B, the interaction between factor A and factor D also have effects on the dimension accuracy. The optimum factors combination of the integral SL system is concluded by using ANOVA. With the optimum factors combination, an error of ±10μm has been reached using the integral SL system. Confirmation experiment results indicated that the dimension accuracy has been significantly improved with the optimum factors combination