Abstract: This paper summarizes research advances of combine based on precision agriculture at home and abroad and especially introduces the information technology of intelligent estimation of yield. Because the foreign combine of precision agriculture has not stressed the control of working quality so they are not suitable for the situation of China. The paper discusses the technical ideas of monitoring and controling efficiency and working quality, prospects the trend of research and development of Chinese combine. Then the key technology in China precision agriculture is thought of as the intelligent estimation of yield and the control of working quality.