The invention provides a three-dimensional profile scanning device and method of dual-line laser. The device comprises a first line laser device, a second line laser device, a motion translation device, an image acquisition device and a control and data processing device, wherein the first line laser device is used for transmitting line laser for measuring in a first scanning angle; the second line laser device is used for transmitting line laser for measuring in a second scanning angle; the motion translation device is used for carrying a measured object to perform translation motion; the image acquisition device is used for performing image acquisition on a line laser scanning image of the measured object; and the control and data processing device is used for controlling the motion translation device to move, controlling the image acquisition device to acquire the line laser scanning image of the measured object, receiving and processing the line laser scanning image, aligning the data of the same profile, and removing non-aligned secondary reflection point data caused by different secondary reflection point positions, thereby obtaining three-dimensional profile information of an actual object. The three-dimensional profile scanning device of dual-line laser is especially suitable for performing high-precision three-dimensional profile scanning on complicated and smooth metal surfaces.