The invention specifically relates to a school air environment early warning system, which comprises an environment monitoring sensor component, a signal conditioning module, a central processing unit, a driving control module, a campus broadcasting device, a storage module and a wireless communication module, wherein the environment monitoring sensor component is connected with the central processing unit through the signal conditioning module; the central processing unit controls the campus broadcasting device to be started and shut down through the driving control module; and the storage module and the wireless communication module are independently connected with the central processing unit. By use of the device, the campus environment can be monitored, and in addition, when the environment parameter exceeds a set value, broadcasting can be carried out through a campus broadcast so as to perform a good prompt function. Meanwhile, the system has the advantages of simple structure and high intelligentizing degree and is very suitable for schools.