Aiming at various content and many problems of computer group board level debugging, put forward a new debugging method. Based on the debugging technical process, give related debugging methods for D/A transformation function and step length of laser blanking plate input/output pulse hysteresis. Debug D/A plate transformation and analog output function. Use measuring related hysteresis step length to acquire accurate debugging step length. Practice has proved that 2 debugging projects taken by the debugging method, which is not only reduces the computer combination board-level debugging cycle, but also improve the precision of debugging.