The living environment of human beings is being affected by various types of radiation. Among them, natural radiation has the largest dose. If the dose of natural radiation exceeds a certain threshold level, people will face health risks on multiple fronts. In this work, researchers measured the air-absorbed dose rate at 1 meter above different surface environments on campus and estimated the effective dose equivalent of environmental gamma radiation to the residents. Experiments and analyses show that the radiation level on campus was evaluated based on the measurements. The order of the amount of the radiation dose rate is granite pavement > cement pavement > asphalt ground. According to the experiments, the radiation content of external exposure in the campus is already slightly higher than the limit, i.e. 1mSv/y.