The invention relates to an injection-reduction and up-to-standard emission method for high-sulfur-content wastewater of an oil and gas field. The method adopts a technology including negative-pressure desulfurization, chemical catalytic oxidation, flocculation settlement, organic membrane filtering, ozone catalytic oxidation and high-pressure reverse osmosis and can realize the aim of deeply removing sulfide, suspension matters, organic matters, chloride and oil in the high-sulfur-content wastewater of the oil and gas field; the sulfur content, suspension matter content and oil content of finally-obtained high-pressure reverse osmosis concentrated water meet reinjection water standards of the oil and gas field; the water produced by the high-pressure reverse osmosis meets up-to-standard emission standards.