The invention relates to a bedroom night air-exchange method through light polycondensation and transmission, a bedroom night air-exchange apparatus through light polycondensation and transmission comprises a light collection device, a light transmission apparatus, an optical medium, titanium dioxide particles, a gas storage container, a minisize air exhauster, a pipeline, and a switch. The method is characterized in that oxygen molecules and water molecules in air at daytime are excited to the free negative ions air having oxidation force and stored by the gas storage container, free negative ions air can be slowly released to bedroom at evening and daytime, the free negative ions having the oxidation force are combined with bacteria virus in bedroom, then bacteria virus in the bedroom dead, the oxygen molecules and water molecules are excited to the free negative ion air having oxidation force used for being breathed by people in bedroom, so that oxygen molecules and water molecules are excited to free negative ions having the oxidation force for oxidizing organic matters and partial inorganic substances in air in bedroom, and the air in the bedroom can be refreshed.