An energy distributive purifying and pipeline-free purifying type central ventilation system, compared with a device capable of purifying 500m<3> fresh air volume per hour, is characterized in that the normal air volume is not beyond 40%, and the rest time is about 20%. Namely, if the normal heat recovery rate of the compared device is less than 60%, and the normal heat recovery rate is less than80% at night, the causing heat loss is beyond that of the system; if the ratio of electrically supporting heating to reach equitemperature is normally less than 60%, and ratio of electrically supporting heating to reach equitemperature is less than 80% at night, the causing temperature decrease is beyond that of the system. The power consumption of the system is less than that of the compared device. The system is free from compared heat exchange and electric heating supporting device consumption; the annular material consumption cost of the system is less than 1000 Yuan; the PM2.5 index in aroom is kept at optimal level after the system is started for 2h. The result of the inspection performed based on the national standard inspection method shows that people can safely live in the roomafter the system runs for 5h in case that the pollutants such as formaldehyde, benzene and TVOC in air in the room are about 400% beyond the standard value (traditionally publicized formaldehyde pollution is 300% beyond the standard value). Therefore, a decorated house can be used once being decorated; the idle period of the decorated house is reduced from 6 and 7 months to 0, and thus wealth is created for a user.