Abstract: The measuring principle and characteristic of microwave moisture content determination techniques are analyzed，and a method is addressed as well.According to the relationship among the power attenuation，signal parameter variation and moisture content of grain when the microwave penetrates the grain，a model of microwave moisture content measuring system is built.Experiments are made to compare the algorithm with traditional method on solving this problem.The results show that this method can measure the grain moisture content quickly and efficiently，and satisfy the requirement of grain moisture content determination in grain depot.

Key words: microwave, grain moisture content measurement, dielectric constant, non-destructive detection

摘要： 分析了微波水分检测技术的原理、特点及所采用的方法。针对微波透射过粮食后，其反射波的能量衰减，信号参数变化与介电常数及粮食水分含量之间的关系，构建了储粮水分检测模型。测量结果与传统的烘干法所得到的水分含量比较，比较结果表明，利用微波法能够快速、准确地检测出储粮水分含量，满足粮仓储粮含水量检测的需求。

关键词: 微波, 储粮水分检测, 介电常数, 无损检测