Abstract: The W-Nb alloy single crystal rod with diameter of 22 mm and length of 150 mm was prepared by the electron beam floating zone melting method. The misorientation angle of the single crystal, chemical composition, impurity element content and microstructure were analyzed. The analysis results show that the misorientation angle is less than 8°, and total content of impurity element is less than 200 ppm. The W-Nb alloy single crystal rods have good straightness, bright surface and no cracks.