Disclosed are a method and a device for biomass gasification by cycling of carbon dioxide without oxygen. Concretely the method and the device are integrated, wherein carbon dioxide is used as the only gasifying agent for gasifying biomass and other solid fuels into high-quality synthesis gas, the carbon dioxide in the synthetic gases is recovered, and the carbon dioxide produced in the succeeding process using the synthetic gases is recycled for gasification. The purpose of zero emission of carbon dioxide of the whole system is achieved. The advantages of no oxygen consumption, the production of high-quality synthesis gas, high cold gas efficiency and simple operation are achieved. Zero emission of carbon dioxide of the whole system is achieved.