The invention provides a water gas desulfurization system. The system comprises an oil remover, a crude desulfurization tower, a first gas heat exchanger, a gas cooler, a gas-liquid separation device, a desulfurization and decarburization tower, a first fine desulfurization tower and a second fine desulfurization tower, wherein an inlet of the crude desulfurization tower is connected with an outlet of the oil remover; a first inlet of the first gas heat exchanger is connected with an outlet of the crude desulfurization tower; an inlet of the gas cooler is connected with a first outlet of the first gas heat exchanger; an inlet of the gas-liquid separation device is connected with an outlet of the gas cooler; an inlet of the desulfurization and decarburization tower is connected with an outlet of the gas-liquid separation device, and an outlet of the desulfurization and decarburization tower is connected with a second inlet of the first gas heat exchanger; an inlet of the first fine desulfurization tower is connected with a second outlet of the gas heat exchanger; an inlet of the second fine desulfurization tower is connected with an outlet of the first fine desulfurization tower; the first fine desulfurization tower and the second fine desulfurization tower are filled with a JTZX type normal temperature activated carbon fine desulfurization agent.