The invention provides a residue splashing method for stabilizing converter hearth residue thickness under a low-residue smelting condition, which is a residue splashing operation after 300-ton converter smelting steel-tapping is completed. The residue splashing method comprises the following steps of: adopting a six-pore taper oxygen lance, wherein the mach number of a spray head is 2.1, and the flow rate of the residue splashing nitrogen gas is 1000Nm/minute; and selecting different residue splashing schemes according to the difference of final-point oxygen content of the converter. According to the residue splashing method for stabilizing converter hearth residue thickness under the low-residue smelting condition disclosed by the invention, by optimizing the residue splashing gun position and optimizing the proportion of the slag preparing agent, the hearth erosion in the converter smelting is reduced, the residue thickness at the converter hearth is stabilized, the material consumption is lowered and the cost is saved.