The invention discloses a field planting carbon dioxide sensor which comprises a barrel and an end cover. The bottom of the barrel is sealed, external threads are arranged on the side walls of the top of the barrel by means of machining, internal threads are arranged on the inner surfaces of the side walls of the end cover by means of machining, the barrel and the end cover are rotationally fixedly connected with each other in a threaded manner, a gas inlet hole is formed in the center of the end cover, a grid support is arranged near an end of the barrel, reinforcing rib plates which are connected with the side walls of the barrel are arranged at the bottom of the grid support, a carbon fiber net is arranged on the grid support, and a carbon dioxide probe is arranged below the grid support and is connected with a transmission cable. The field planting carbon dioxide sensor has the advantages that the field planting carbon dioxide sensor is easy and convenient to detach and easy to clean and operate, and the probe can be effectively prevented from being contaminated.