A 14-bit multiplying D/A converter was designed. A piecewise current mode R-2R resistor network structure with high 3-bit thermometer code and low 11-bit binary code was adopted to avoid the disadvantages of large switch size and difficult layout matching of high resolution binary current mode R-2R resistor network. The circuit was fabricated in a mixed signal CMOS process. The measured DNL was within ±0.5 LSB, and the INL was within ±0.8 LSB, which was suitable for the applications of industrial control and instrumentation.