Small circulating grain dryer is a kind of small grain dryer developed by our company based the continuous grain dryer. The circulating drying process of the machine solves the problem of small grain dryer that can't dry high-moisture raw grains due to the short time of drying. During operation of the machine, as raw grains fail to reach the safe-moisture level after dried for the first time, they will then be circulated into the dryer for the second drying with the circulating delivery system. The moisture level of grain will be tested in real time at the exit of dryer. Until the safe-moisture level of grain is reached, will the discharge valve be started to discharge the grain out of the dryer.