This paper designs an automatic metal drill pipe straightening system using ATmega128A as controller for. The system is composed mainly of the work piece rotation system, bending detection system, straightening system, laser detection system and the main control circuit. It creatively gives a method of bending metal pipe detection based on touch screen technology. This method is a creative application of touch screen technology in bending test field. Straightening system using PID control algorithm improves the straightening accuracy of drill pipe. After the system simulation and test, it achieves the desired goals.