In order to make steel board cutting more easily and conveniently, green line laser alignment is always being precisely designed to make it equipped with those of laser cutting machine or other kind of cutting mechanics. With the positioning of green reference line, laser cutting machine will always make the easiest cutting of steel boards with the green noncontact reference line. Without the help of other people to make calibration with line or other line projecting tool, this green line projecting alignment laser can be easily mounted on machine or equipment. Whatever kind of operating fields, this 532nm green line projecting laser alignment has just made the most convenient, rapid, and direct line projection on all steel board cutting occasions efficiently.