Abstract: In order to study diffraction characteristics of an external cavity diode laser based on dual volume Bragg gratings, a Bragg grating and a transversely chirped Bragg grating were used to compose the dual volume Bragg gratings. The diffraction characteristics of the volume Bragg gratings before and after the combination were analyzed theoretically. The output spectral characteristics of the external cavity diode laser based on dual volume Bragg gratings were studied. The experimental results show that, under the action of the external cavity feedback of the dual volume Bragg gratings, the dual wavelengths can be output simultaneously. By moving the transversely chirped Bragg grating in the lateral direction, it is possible to keep the other one wavelength tuning linearly in the range of 800nm~815nm. This study provides experimental guidance for high-power diode lasers based on dual volume Bragg gratings for dual wavelength output.