Guiding ideology and objective of new agricultural science and technology service system in Beijing City are introduced based on the development status of agricultural science and technology service system in Beijing. Then, the six components of new agricultural science and technology service system in Beijing City are analyzed, which are government department system, public welfare extension agency system for agricultural technology, agrotechnical extension agent system at village level, scientific research institution system, peasants economic cooperative organization system, and agriculture-related enterprise system. And the three transmission routes of agricultural science and technology service are also put forward, such as public welfare service route of agricultural science and technology, operating service route of agricultural science and technology, and supporting route of agricultural science and technology. Among them, operating service route can be divided into government-guided industrialization transmission route and market-oriented technology transmission route. Finally, concrete ideas for establishing the new agricultural science and technology service system in Beijing City are discussed from four aspects, including mechanism construction, talent team construction, institution and organization construction, and support and guarantee.