Programmable logic controller, since it is with high reliability, and easy to make central control, its application is widely used in industrial controls. A bridge type crane control method which takes Mitsubishi FX2N series PLC as control core unit was designed, giving out control trapezoid cliagram and program diagram under various working method. Results show that it enables equipment to reach safety and reliability in operation, to reduce labor strength of the operator to raise working efficiency, showing the advantage of PLC in control field.