The invention discloses a full autotrophic nitrogen removal reaction device, which comprises a reactor body. The reactor body comprises an autotrophic nitrogen removal unit and an interception unit; the autotrophic nitrogen removal unit comprises a water inlet layer, a carrier layer and a sediment layer sequentially communicating from top to bottom; the bottom part of the sediment layer communicates with the bottom part of the interception unit; a water distribution pipe is arranged in the water inlet layer and communicates with a water inlet; an air outlet is formed in the top part of the water inlet layer; multiple aerator pipes and multiple mesh-shaped clapboards sequentially arranged up and down are arranged in the carrier layer; an isolation space is formed between two adjacent mesh-shaped clapboards; kieselguhr is filled in the isolation space; a water outlet is formed in the upper part of the side wall of the interception unit. The invention provides the full autotrophic nitrogen removal reaction device which is capable of improving the ecological diversity and the biomass of the system, improving the nitrogen removal performance and the operation stability, and reducing theoperation cost of the autotrophic nitrogen removal system.