A system for cleaning, zeroing, and preventing air pollution in indoor space includes several gas detection devices (A, 3), a central control monitoring device (B), and several gas exchange and filtration devices (C). The gas detection devices (A, 3) detect and output indoor and outdoor air pollution data. The central control monitoring device (B) receives the outdoor and indoor air pollution data to perform an intelligent computation and comparison, locate an air pollution location in the indoor space, and transmit a control command intelligently. Each of the gas exchange and filtration devices (C) is combined with a smart switch (D) for the control command to control the gas exchange and filtration devices (C) to be enabled, so that the air pollution is filtered and exchanged by the gas exchange and filtration devices (C), thereby allowing the indoor air pollution data detected by the gas detection devices (A, 3) in the indoor space to be a safety detection value.