The distribution of reducing gas in melter gasifier of COREX-3000 directly influences gas utilization and burden descent.The charging of burden is a main method of regulating gas flow distribution.In order to reveal the burden distribution process，a mathematical model of forecasting the burden pile profile is established based on the impact position，angle of repose and the mass conservation of burden.The impact position of burden is determined by analyzing the material flow trajectory and force during charging process.Based on the mathematical model，an extended burden pile profile prediction software of COREX-3000 melter gasifier is developed by combining mathematic knowledge and computer technology.Using this software，the burden trajectory，the impact position and the burden pile profile under various operations of the coal-gimbal distributor and the DRI-flap distributor can be easily obtained，which can provide reference data for adjusting the charging operation in practice.