The function of digital circuits is usually accomplished by CPLD. The function of integrated analog circuits realized with CPLD is discussed. Two methods of controlling the pulse width of monostable trigger are studied. One is realizing monostable trigger with external RC , the other is controlling the pulse width with external signal. The experimental results show that controlling the pulse width of monostable trigger with CPLD on the basis of full digital ciruits effectively helps the realization of miniaturization of laser fuse circuit system and increases the reliability of the circuits.