The invention provides a high-efficiency denitrification nitrogen removal device and a high-efficiency denitrification nitrogen removal method. The device comprises a water inlet part, a reaction part and a three-phase separation part which are sequentially connected in series, wherein the water inlet part comprises a water inlet used for allowing sewage and solid electron donors to enter; and autotrophic denitrification floras are arranged in the reaction part. When the sewage is treated by utilizing the nitrogen removal device disclosed by the invention, the nitric nitrogen treatment efficiency is high, secondary pollution is avoided, and the cost is low.