A small drying and refrigerating dual-purpose heat pump system for batch processing agriculture products was developed. The system was featured with low cost, improved structure of insulated room and new wet discharge-cycle air duct. heat pump selection of mixed refrigerant aimed at the drying highest temperature and the lowest refrigeration temperature respectively was 75 ℃ and 5 ℃. These reach results demonstrated that the system was stable, meet the design requirements of the high limit temperature and dehydrate rate in dry heating mode, and work well in keep-fresh mode.