The invention provides a flue gas treatment method for simultaneous low-temperature photocatalytic self oxidation reduction, desulfurization and denitrification. The flue gas treatment method comprises the following steps: through an self oxidation reduction catalyst acted on a flue gas containing sulfur dioxide and nitric oxide gases under a low-temperature photocatalytic condition, carrying out self oxidation reduction between sulfur dioxide and nitric oxide; transforming sulfur dioxide into sulfur, cooling and recovering elemental sulfur; and transforming nitric oxide into nitrogen dioxide, absorbing by alkali liquor and recovering nitrate and nitrite. Therefore, the targets of simultaneous treatment on waste, catalytic self oxidation reduction, desulfurization and denitrification can be reached; a high-value-added product elemental sulfur can be recovered; tail gas can reach the current emission standard; the desulfurization efficiency is over 95%; the denitrification efficiency is over 70%; the recovery rate of the elemental sulfur is over 95%; and the recovery rate of NO2 is over 97%.