Objective To investigate the biaxial vector control precision of x-y stage under 3D printers. Methods The article introduced the mathematical model of permanent magnet motor, meanwhile described the outline of the system and analyzed the error of variable gain cross coupling vector control algorithm. The Matlab / Simulink software was used for simulation and analysis of the biaxial controlled variable gain cross coupling vector control algorithm. Results The simulation results showed that the variable gain cross coupling vector control algorithm could control the contour error within 0.01 mm. Conclusion By varying the gain cross-coupling algorithm, system robustness was improved, and the outline of the system error was reduced.