The invention discloses an edge plane shape control method of large-expansion-ratio high strength grade pipeline steel, belonging to the technical field of a heavy and medium plate rolling technology. Proper technical parameters are controlled in a three-stage process for rough rolling of a heavy and medium plate mill. Variable cross-section thickness rolling is performed at a forming pass of the first stage of the rough milling, so that a digging effect is formed at a middle position in the length direction after the steel plate is rolled, the middle position of the steel plate is thinner than the head and the tail of the steel plate, and the thickness difference is delta h. Next, a plate blank is revolved at an angle of 90 degrees and then is expanded, and the length of the steel plate is changed into the actual rolling width at the time; and since the thickness in the width direction is different, the reduction rate from the plate edge to the plate center is also different, thereby improving the edge plane shape. The yield is improved, and the production cost is reduced.