The theoretical analysis of galvanometer scanning system widely using in the technology is described. It's shown that the relationship between the deflection angles of the 2-D galvanometer scanner and the corresponding X-Y coordinates value is nonlinear. A practical method is put forward in the research. Its basic principle is that a correction table is done through comparing the theoretical data with the corresponding data in laser scanning,then the distortion and the others errors are corrected according to a interpolating algorithm. The correction technology is suitable for all 2-D scanning system using two galvanometer scanner,and can correct any laser Rapid Prototyping equipment applying the principle of two galvanometer scanner.