Abstract: After several decades of continuous development，MHP (Multiple Hole Plug) porous plug has become one of the main form of gas supply components. In the current paper，the converter bottom blowing process was calculated theoretically，and the MHP element parameters matching with the gas flow rates were calculated. The results showed that，the MHP bottom blowing had a favorable flow range，which was limited by facility and external pressure. Bottom blowing flow rate was directly proportional to the bottom blowing outlet pressure with clear conversion relationship. Under the certain blowing flow rate，MHP parameters should be selected carefully.

Key words: converter bottom blowing, MHP, gas flow rate, gas pressure, theoretical calculation