社会的发展、科技的进步，离不开电子产业的推动。电子技术的提高代表了一个国家整体的实力，电子产品领域的高、精、尖技术的发展都需要更加精密，更加多样的电子测量仪器与之配合支持。因此，先进的测量仪器成为电子产品开发的必备条件，也是电子行业发展的重中之重。所以，对高精度便携式数字万用表的研究有着非常重要的意义。 本文主要研究了基于MSP430单片机的50000字便携式数字万用表。首先介绍了各测量功能与测量算法的原理，并列出了公式，就测量过程产生的误差进行了分析，最终给出其主要产生的根源，提出校正策略。设计了以MSP430F2416为核心处理器，以CS5524，LC4064为模数转换芯片的数字万用表的硬件结构，整个硬件系统由MSP430微处理器、模拟量输入模块、基于工I2C总线的外围扩展模块、通讯模块、显示模块七大部分组成。最后详细地介绍了系统的软件设计，以模块化设计思想提供了该数字万用表的软件设计过程，实现了包括系统程序模块、AD数据采集与处理模块、CPLD数据采集与处理模块、按键、刀盘及液晶显示模块等。 通过对研制的万用表进行测试，列出了实验数据，验证了上述研究和设计的可行性与可靠性。目前系统实现的功能及运行情况表明，该数字万用表精度可以达到50000字的要求，功能丰富，性能稳定。

Social development, scientific and technological progress, have been driven by the electronics industry. The development of electronic technology is improved the strength of the country as a whole, more diverse functions of electronic measuring instruments with the cooperation and support. This more sophisticated electronic measuring instrument becomes a prerequisite for product development as well as the most important development of the electronics industry. Therefore, the study of high-precision portable digital multimeter has a very important significance. The paper was targeted for 50000 words portable digital multimeter based on MSP430 MCU, First introduced the theory of the various of measurement function and measurement algorithm, listed the formula and analyzed the error of Measurement process. Given its main causes, Proposed correction strategy; Designed as the core processor to MSP430F2416, LC4064 chip for analog-digital conversion of the digital multimeter of hardware structure, the entire hardware system Composed by the MSP430 microprocessors, communication module, display module . The final details on the system software design, this paper from the perspective of the system to the modular design concept of the digital multimeter to provide software design process, AD data acquisition and processing module, CPLD data acquisition and processing module, and key cutter features such as liquid crystal display. Through testing the developed multimeter, verifying the feasibility of top study and design. The current system functions and operation show that the accuracy of the digital multimeter can be achieved the requirements of 50000 words, feature-rich, stable performance.