Hot metal dephosphorization method by using top-bottom combined blown converter under the condition of slag splashing and converter protecting

The invention is a hot metal dephosphorization method by using a top-bottom combined blown converter under the condition of slag splashing and converter protecting, belonging to the technical field of the steelmaking and mainly aiming at the hot metal dephosphorization under the condition of slag splashing and converter protecting. The method comprises the following steps: carrying out slag splashing and converter protecting by lance top-blown inert gas; adding dephosphorization agent into the hot metal bath level through a hopper mounted above the converter; supplying oxygen gas for the hot metal bath level from the top part by an oxygen lance; supplying inert stirred gas to the inside of the hot metal through an air supply system mounted on the bottom of the converter; effectively using the slag and the protection lining of the last heat and improving the dephosphorization efficiency through the operation of slag splashing and converter protecting. The invention has the advantages that the slag and the protection lining of the last converter-order is fully used, the dephosphorization efficiency is improved through the operation of slag splashing and converter protecting, and the final phosphorous content can be controlled below 0.02% by mass percentage.