A night vision device, comprising: a first light-sensitive chip which is at least able to sense infrared light; a first lens group (101, 201, 301) which is used to image onto the first light-sensitive chip; a first display (102, 202) which is arranged to display an image collected by the first light-sensitive chip; an image processing system which is arranged to process image data collected by the first light-sensitive chip, wherein the image processing system has a digital zoom capability and/or the first lens group has an optical zoom capability; and a control system which is arranged to adjust an imaging range of the first light-sensitive chip by adjusting an optical zoom factor of the first lens group and/or a digital zoom factor of the image processing system; wherein the night vision device further comprises: an auxiliary illumination unit (103, 203, 303) which comprises an auxiliary light source and a light guiding cavity, wherein, the auxiliary light source is at least able to emit infrared light, a light emitted by the auxiliary light source is emitted through the light guiding cavity, the light guiding cavity has a movable adjustment component which is arranged to adjust an irradiation range of emitted light manually or automatically by the control system, and the irradiation range is adapted to the imaging range of the first light-sensitive chip, characterized in that an inner wall of the light guiding cavity has reflectivity, the light guiding cavity comprises a light collection cavity and a guiding pipe which are connected with each other, the auxiliary light source is enclosed in the light collection cavity and is arranged to emit J Z light via the guiding pipe connected with the light collection cavity, and the guiding pipe is used as the movable adjustment component and is telescopic, wherein when the guiding pipe is elongated, the divergence angle of the light emitted is reduced, and when the guiding pipe is retracted, the divergence angle of the light emitted is increased. a first light-sensitive chip which is at least able to sense infrared light; a first lens group (101, 201, 301) which is used to image onto the first light-sensitive chip; a first display (102, 202) which is arranged to display an image collected by the first light-sensitive chip; an image processing system which is arranged to process image data collected by the first light-sensitive chip, wherein the image processing system has a digital zoom capability and/or the first lens group has an optical zoom capability; and a control system which is arranged to adjust an imaging range of the first light-sensitive chip by adjusting an optical zoom factor of the first lens group and/or a digital zoom factor of the image processing system; wherein the night vision device further comprises: an auxiliary illumination unit (103, 203, 303) which comprises an auxiliary light source and a light guiding cavity, wherein, the auxiliary light source is at least able to emit infrared light, a light emitted by the auxiliary light source is emitted through the light guiding cavity, the light guiding cavity has a movable adjustment component which is arranged to adjust an irradiation range of emitted light manually or automatically by the control system, and the irradiation range is adapted to the imaging range of the first light-sensitive chip, characterized in that an inner wall of the light guiding cavity has reflectivity, the light guiding cavity comprises a light collection cavity and a guiding pipe which are connected with each other, the auxiliary light source is enclosed in the light collection cavity and is arranged to emit J Z light via the guiding pipe connected with the light collection cavity, and the guiding pipe is used as the movable adjustment component and is telescopic, wherein when the guiding pipe is elongated, the divergence angle of the light emitted is reduced, and when the guiding pipe is retracted, the divergence angle of the light emitted is increased. an auxiliary illumination unit (103, 203, 303) which comprises an auxiliary light source and a light guiding cavity, wherein, the auxiliary light source is at least able to emit infrared light, a light emitted by the auxiliary light source is emitted through the light guiding cavity, the light guiding cavity has a movable adjustment component which is arranged to adjust an irradiation range of emitted light manually or automatically by the control system, and the irradiation range is adapted to the imaging range of the first light-sensitive chip, characterized in that an inner wall of the light guiding cavity has reflectivity, the light guiding cavity comprises a light collection cavity and a guiding pipe which are connected with each other, the auxiliary light source is enclosed in the light collection cavity and is arranged to emit J Z light via the guiding pipe connected with the light collection cavity, and the guiding pipe is used as the movable adjustment component and is telescopic, wherein when the guiding pipe is elongated, the divergence angle of the light emitted is reduced, and when the guiding pipe is retracted, the divergence angle of the light emitted is increased.