Abstract: Before entering tower dryer, the harvested paddy rice with high moisture content, which contains many fiber impurities, such as broken crop leaves, straws, etc., must be cleaned. Aiming at the present situation that there are few reports about cleaning technology for high moisture content paddy rice at home and abroad and current paddy cleaners are not suitable for treating high moisture paddy rice, so combined cleaners were designed. Interrelationship and interaction among parameters, namely, treating capacity with moisture content of paddy rice, air suction volume of equipment, sieve size and distribution, the tilt angle of sieve-plate and distribution, vibrating frequency, etc., were analyzed by production experiment. Tested results show that when the moisture content of paddy rice is higher than 20%, sieve size of the combined cleaner should be distributed according to the upper layer 50×50, the middle 30×30 and the lower 15×15, and the tilt angle of sieve-plate should be arranged according to the upper layer 21°, the middle 17°and the lower 13°. Besides, actual wind velocity passing through sieve size should reach 1.1 to 1.2 times of suspension velocity of paddy rice itself so that treating capacity can be larger and cleaning effect can be better.