The invention relates to a steel ladle powder injection desulfuration refining process for low-sulfur steel production. The process is characterized in that: 3.0 to 6.5kg/t of aluminum iron for strong deoxidation is adopted in converter tapping; 0.4 to 0.6kg/t of aluminum for slag surface deoxidation is added on the steel ladle slag surface after tapping is finished; the oxidation property (FeO%+Mn%) of station reaching top slag of steel ladles is less than or equal to 3.5 percent; the temperature of the molten steel reaching a powder injection desulfuration station is 1,610 to 1,640 DEG C, and Alt in the steel is 0.040 to 0.090 percent; the working pressure of steel ladle powder injection desulfuration delivery carrier gas is 3.0 to 4.0bar, and the flow is 40 to 60m<3>/h; and the powder injection velocity of steel ladle powder injection desulfuration is 40 to 60kg/min, and the consumption of the injection powder is 4.0 to 6.0 kg/t of steel. After the steel ladle powder injection desulfuration process is adopted, the sulfur content of the steel can be reduced from 50-80ppm to within 12ppm, and the desulfuration rate can reach 78.0 to 85.0 percent.