A substrate inspection device includes a laser emitting unit, arranged at one side of a transmission device, and configured to emit a laser beam to each substrate to be inspected on the transmission device when the substrate to be inspected is moved to an inspection position; a laser receiving unit, arranged at the other side of the transmission device, and configured to receive the laser beam transmitted through the substrate to be inspected; and a calculation unit, configured to calculate transmissibility of the laser beam relative to the substrate to be inspected based on an intensity of the laser beam emitted by the laser emitting unit and an intensity of the laser beam received by the laser receiving unit, and determine whether a line width of a black matrix in the substrate to be inspected is within a predetermined range of the line width based on the transmissibility.