A method for improving 3D image depth information, wherein the method comprises: acquiring a raw 3D image, performing first-time exposure on the raw 3D image, and generating a first exposure image; acquiring an effective pixel point in the first exposure image, and if a quantity of effective pixel points meets a preset condition, extracting the effective pixel point in the first exposure image; otherwise, performing second-time exposure on the raw 3D image, and generating a second exposure image; and if a quantity of effective pixel points in the second exposure image meets the preset condition, extracting the effective pixel point in the second exposure image; otherwise, continuously performing exposure and generating a corresponding exposure image, determining whether the quantity of effective pixel points of the exposure image meets the preset condition until an exposure time reaches an exposure time threshold or a quantity of effective pixel points in the corresponding exposure image generated through exposure meets the preset condition, and extracting an effective pixel point in the exposure image; and demarcating and calibrating the effective pixel point, and generating a 3D depth information map; wherein the acquiring an effective pixel point in the first exposure image specifically comprises: acquiring the pixel point of the first exposure image, and determining whether the pixel point meets a preset signal quality parameter; and if the pixel point meets the preset signal quality parameter, marking the pixel point as an effective pixel point, and acquiring all effective pixel points in the first exposure image; wherein before the acquiring a raw 3D image, performing first-time exposure on the raw 3D image, and generating a first exposure image, further comprising: presetting an exposure time gradient array, the gradient array comprising exposure times with several time lengths arranged in ascending order, wherein an exposure time with the maximum time length is an exposure time threshold. acquiring a raw 3D image, performing first-time exposure on the raw 3D image, and generating a first exposure image; acquiring an effective pixel point in the first exposure image, and if a quantity of effective pixel points meets a preset condition, extracting the effective pixel point in the first exposure image; otherwise, performing second-time exposure on the raw 3D image, and generating a second exposure image; and if a quantity of effective pixel points in the second exposure image meets the preset condition, extracting the effective pixel point in the second exposure image; otherwise, continuously performing exposure and generating a corresponding exposure image, determining whether the quantity of effective pixel points of the exposure image meets the preset condition until an exposure time reaches an exposure time threshold or a quantity of effective pixel points in the corresponding exposure image generated through exposure meets the preset condition, and extracting an effective pixel point in the exposure image; and demarcating and calibrating the effective pixel point, and generating a 3D depth information map; wherein the acquiring an effective pixel point in the first exposure image specifically comprises: acquiring the pixel point of the first exposure image, and determining whether the pixel point meets a preset signal quality parameter; and if the pixel point meets the preset signal quality parameter, marking the pixel point as an effective pixel point, and acquiring all effective pixel points in the first exposure image; wherein before the acquiring a raw 3D image, performing first-time exposure on the raw 3D image, and generating a first exposure image, further comprising: presetting an exposure time gradient array, the gradient array comprising exposure times with several time lengths arranged in ascending order, wherein an exposure time with the maximum time length is an exposure time threshold. acquiring the pixel point of the first exposure image, and determining whether the pixel point meets a preset signal quality parameter; and if the pixel point meets the preset signal quality parameter, marking the pixel point as an effective pixel point, and acquiring all effective pixel points in the first exposure image; wherein before the acquiring a raw 3D image, performing first-time exposure on the raw 3D image, and generating a first exposure image, further comprising: presetting an exposure time gradient array, the gradient array comprising exposure times with several time lengths arranged in ascending order, wherein an exposure time with the maximum time length is an exposure time threshold.