A semi-steel converter steelmaking method

The invention discloses a semi-steel converter steelmaking method, comprising the following steps of: (1) in the time period from the beginning of blowing to a moment in the range from 75 to 105 s, controlling the height of an oxygen lance within the range from 2.5 to 3 m and the oxygen supply strength within the range from 1.2 to 1.5 m /(min.t steel), and slagging; (2) in the process from 75-105 s after the beginning of blowing to the mass fraction of carbon in liquid steel in the range from 0.20% to 0.40%, controlling the height of the oxygen lance within the range from 2 to 3 m and the oxygen supply strength within the range from 2.5 to 3.5 m /(min.t steel); (3) deslagging when the mass fraction of carbon in the liquid steel is in the range from 0.20% to 0.40%; and (4) carrying out secondary slagging and blowing after deslagging until the finishing point of blowing. The semi-steel converter steelmaking method provided by the invention is capable of preventing a dry dedusting system from explosion venting and also capable of effectively removing phosphorus in the liquid steel.