The invention discloses a 
smelting process for producing low-carbon ultralow-
phosphorus steel in a converter. The 
smelting process comprises the following steps of: dephosphorizing molten iron desulfurized once by utilizing two times of slagging blowing process, namely, an early stage and a later, or three times of slagging blowing process, namely, an early stage, a middle stage and the later stage, or multiple times of slagging blowing process, wherein the content of 
phosphorus of the molten iron is 0.11-0.13%; utilizing 
silicon iron 
slag regulation, pouring the 
slag into a 
slag basin until the slag basin is full each time and controlling process temperature; pouring slag when 
oxygen blowing is carried out by 40-45%, wherein the target temperature of an early stage is 1,350-1,400 DEG C; and controlling the temperature between 1530 DEG C and 1550 DEG C when a sublance is used for blowing 
oxygen for 80%, and pouring the slag, so that the low-carbon ultralow-
phosphorus steel with terminal phosphorus content being within 0.005% is obtained, wherein the terminal target temperature is 1560-1580 DEG C. The 
smelting process for producing the low-carbon ultralow-phosphorus steel in the converter, disclosed by the invention, can carry out multiple times of slagging on the molten iron desulfurized once in the converter and has the advantages of being small in molten iron physical heat loss, high in yield and efficiency, low in 
alloy consumption and cost, and energy-saving.