随着精准农业的发展，农业种植和农业研究人员需要一种手持式NDVI测量仪，以便对农作物长势进行定量测量。本文讨论了一种手持式NDVI测量仪的完整设计过程，详细论述了设计原理，并给出了详尽的单片机程序、设计电路原理图及PCB图。该NDVI测量仪采用太阳光作为光源，光电探测器采用滤光片和光敏二极管实现，用AT89C51单片机控制。其具有结构简单、成本低、轻便、低功耗的特点。-With the development of precision agriculture and farming, and agricultural researchers need a handheld NDVI measuring instrument, in order to crop growth for quantitative measurement. This paper discusses a handheld meter NDVI the integrity of the design process, discussed in detail the design principles, and gives a detailed SCM procedures, circuit schematics and PCB plans. The NDVI measuring instrument used sunlight as a light source, photodetector using filters and photodiode realized, with AT89C51 control. Its structure is simple, low cost, lightweight, low-power characteristics.