A moving device used in liquid, comprising: a mode switching member configured to achieve a position switching of the moving device above a liquid surface and below the liquid surface, wherein when the moving device is below the liquid surface, the moving device is fully submerged below the liquid surface, and when the moving device is above the liquid surface, at least a portion of the moving device is above the liquid surface; wherein the mode switching member includes a buoyancy force adjustment assembly, and the buoyancy force adjustment assembly includes: a buoyancy cavity configured to accommodate gas; a buoyancy force adjustment member configured to adjust a volume of the gas in the buoyancy cavity; the moving device comprises a processor, characterized in that the moving device further comprises a first sensor or a second sensor; the first sensor is configured to sense a position of the moving device, the second sensor is configured to detect whether a position of an air inlet of the buoyancy cavity is located in air; when the moving device is to be switched from below the liquid surface to above the liquid surface, the processor is configured to obtain from the first sensor the position of the moving device, or to obtain from the second sensor a detection result of whether the air inlet is located in air, when the position of the moving device meets a preset condition or the detection result indicates that the air inlet is located in air, the processor is configured to control the buoyancy force adjustment member to increase the volume of the gas in the buoyancy cavity. a mode switching member configured to achieve a position switching of the moving device above a liquid surface and below the liquid surface, wherein when the moving device is below the liquid surface, the moving device is fully submerged below the liquid surface, and when the moving device is above the liquid surface, at least a portion of the moving device is above the liquid surface; wherein the mode switching member includes a buoyancy force adjustment assembly, and the buoyancy force adjustment assembly includes: a buoyancy cavity configured to accommodate gas; a buoyancy force adjustment member configured to adjust a volume of the gas in the buoyancy cavity; the moving device comprises a processor, characterized in that the moving device further comprises a first sensor or a second sensor; the first sensor is configured to sense a position of the moving device, the second sensor is configured to detect whether a position of an air inlet of the buoyancy cavity is located in air; when the moving device is to be switched from below the liquid surface to above the liquid surface, the processor is configured to obtain from the first sensor the position of the moving device, or to obtain from the second sensor a detection result of whether the air inlet is located in air, when the position of the moving device meets a preset condition or the detection result indicates that the air inlet is located in air, the processor is configured to control the buoyancy force adjustment member to increase the volume of the gas in the buoyancy cavity. a buoyancy cavity configured to accommodate gas; a buoyancy force adjustment member configured to adjust a volume of the gas in the buoyancy cavity; the moving device comprises a processor, characterized in that the moving device further comprises a first sensor or a second sensor; the first sensor is configured to sense a position of the moving device, the second sensor is configured to detect whether a position of an air inlet of the buoyancy cavity is located in air; when the moving device is to be switched from below the liquid surface to above the liquid surface, the processor is configured to obtain from the first sensor the position of the moving device, or to obtain from the second sensor a detection result of whether the air inlet is located in air, when the position of the moving device meets a preset condition or the detection result indicates that the air inlet is located in air, the processor is configured to control the buoyancy force adjustment member to increase the volume of the gas in the buoyancy cavity.