The invention discloses an acetylene production process operation control method and particularly relates to a displacement and charging operation process DCS control method. An emptying-displacement-charging-reaction process of an acetylene generator is controlled through a DCS, a displacement and charging process is changed into an automatic control mode, a nitrogen filling pressure A value is preset, an automatic replacement time T1 value is set, a time relay is newly added, the time T2 is set, operation starts to reach the A value, a replacement button starts to enter a replacement stage, the replacement time satisfies the T1 and the T2, a next program step is automatically carried out, if the nitrogen filling pressure is determined by the DCS to be smaller than the A value, the replacement time is T1+2 minutes and the T2+2 minutes, the T1+2 minutes and the T2+2 minutes are both satisfied, a next step is automatically carried out, the program is over, all internal switches and valve positions are reset to initial states, a reaction stage is finally entered, and ideal control standards can be realized through the previous operations. The method is further advantaged in that operation is convenient and rapid, influence of artificial factors can be solved, and automatic control and precision for the key acetylene production process are realized.