Provided is a downdraft biomass gasification combustion cooking and heating furnace. A furnace shell is arranged on a base, a feed port is formed in the upper surface of the furnace shell, a primary air chamber, a combustion chamber, a smoke channel, an ash discharge chamber and a cooking stove are arranged in the furnace shell, a lower stove ring is arranged between the primary air chamber and the combustion chamber, and a heat exchanger is arranged in the smoke channel. The downdraft biomass gasification combustion cooking and heating furnace is characterized in that an inclined gasification chamber communicated with an inlet of the primary air chamber is arranged on the upper portion inside the furnace shell, a V-shaped water channel is formed between the gasification chamber and the combustion chamber, a combined grate formed by an inclined fixed grate and a movable grate is arranged in the primary air chamber, an oxygen enrichment ring is arranged on the lower stove ring, a secondary air chamber is formed by a cavity between the lower stove ring and the oxygen enrichment ring, and an oxygen enrichment pipe is arranged on the lower stove ring. The downdraft biomass gasification combustion cooking and heating furnace has the advantages that the downdraft biomass gasification combustion cooking and heating furnace is low in PM2.5, sulfur dioxide and oxide emission index, free of tar, free of ash escape, smokeless, wide in fuel application range, high in thermal efficiency, long in hot standby time, free of reignition, low in fault rate and suitable for rural families.