The invention discloses a display method and system of coal-seam distribution. The display method comprises the following steps of: when entering a one-knife-coal working surface, obtaining a bracket pushing stroke and a bracket-base inclination angle before pushing, and calculating a coordinate point of a lowest point at the position of a first coal mining machine of the one-knife-coal working surface by combination with the previous one-knife-coal working surface; obtaining the position of the coal mining machine, the traction inclination angle of the coal mining machine and the mining height of the coal mining machine in each coal mining operation of the one-knife-coal working surface, further calculating a coordinate point of the lowest point and a coordinate point of the highest point at the position of the coal mining machine in each coal mining operation of the one-knife-coal working surface; connecting the coordinate points of all the lowest points and coordinate points of all the highest points into lines at the position of the coal mining machine in each coal mining operation of the one-knife-coal working surface, and determining the plane by the two lines; connecting and drawing the planes of all the one-knife-coal working surfaces into a coal-seam distribution diaphragm. According to the display method and system disclosed by the invention, the distribution condition of the coal seam can be effectively displayed, and further the strike of the coal seam can be judged.