Agricultural science and technological (S&T) innovation is the important support for consolidating the results of poverty alleviation and comprehensively promoting rural revitalization. China's agricultural S&T innovation is not enough to strongly break the bottleneck and support demand of agricultural development and faced such problems as insufficient effective supply of agricultural S&T innovation, incompatibility between traditional agricultural S&T extension methods and demand of the new types of agricultural businesses, shortage of organization of agricultural S&T service, lack of agricultural S&T talents, and imperfect policy of agricultural S&T innovation. It is suggested that establish a demand-oriented agricultural S&T innovation system from five aspects of innovation, extension, service, talents, and policies, to support effectively support the transition of policy priority from Poverty Alleviation to Rural Revitalization.