A new linear OCD driver is designed to meet the measurement requirements in engineering fields and get rid of the disadvantages of the previous OCD drivers. This driver is developed on the basis of CPLD, and rich interface signals are provided for users with the help of the programmable technology of CPLD. Its key features,principle and design ideas of the timing sequence are presented in detail. It is proved by experiments that this OCD deriver completely meets the design requirements. The whole measurement system can work precisely when this driver is integrated into another measurement circuit.