The invention relates to the field of stainless steel smelting, in particular to a method for reserving slag without reduction for stainless steel. The method for reserving slag without redction for stainless steel includes the steps that firstly, dephosphorization, desulfuration and desilicication are conducted on molten iron; secondly, the molten iron treated in the first step is put into a converter, high-carbon soldering iron is added, oxygen blowing begins, when the temperature is larger than or equal to 1640 DEG C, calcium oxide, magnesium oxide and silicon iron are added for adjusting the components of the molten iron, meanwhile, the components of the molten iron are detected, when set components are reached, steel tapping is conducted but slag discharging is not conducted, then the molten steel treated in the first step is continuously put into the converter, and after the operation is repeated 2-4 times and after the set components are reached finally, steel tapping and slag discharging are conducted; thirdly, tapped steel in the second step is put into a VOD furnace to be refined; and fourthly, the steel refined in the third step is subjected to continuous casting.