It is necessary to dry moist grain before storage in the Northeast and North China after harvest in autumn. Because of the flowability and dispersed moisture content of grain, the rapid, on-line and accurate moisture content measuring is a key problem demanding prompt solution. According to the working state of grain dryer, this paper presents an on-line measuring system of moisture content for grain dryer, which is based on multisensor information fusion technology. The measuring principles, hardware structure and software design were introduced, and the information fusion algorithm was given. The measuring system applies 80C196KC single-chip processor as information processing unit, and has friendly user interface with Chinese display LCD. Practical application indicates that this system has many advantages, such as the long distance signal transmission ability, high accuracy, good reliability and intelligence, which can fully meet the needs of on-line measurement of moisture content for grain dyer.