This machine is four-roller plate rolling machine, top roller is the main drive and do rotation movement, lower roller makes up-down movement to make the plate can get the frication along with length direction, two side rollers makes Up-down movement which is an angel with straight line, which can make the steel plate get the needed plastic deformation. Because adjust the side roller can achieve symmetric bending and asymmetrical bending, the flat end will be very short in theory, comparing with three-roller plate rolling machine, which can save pre-bending procedure and pre-bending device, meanwhile it can make rough leveling of steel plate. It is extensively applied in petroleum industry, chemical industry, boiler, shipbuilding industry, hydroelectricity, metal structure and machinery industry.