本文运用流体的连续性方程和伯努利方程计算了气体混合输入器截面积及其出气口截面积,讨论了小比例气体的出气口和混合器出气口之间距离的大小与小比例气体输气管路压强的关系,从而设计了比例悬殊的两种气体输入混合器,保证了N_2基+C_3H_3保护气输入畅通,又使C_3H_3输气管路呈现正压而避免空气穿入管路的风险。 In this paper, the cross-sectional area of ​​the gas mixing input and its outlet cross-sectional area were calculated by using the fluid continuity equation and the Bernoulli equation. The relationship between the small gas outlet and the outlet of the mixer was discussed. The relationship between the pressure of the gas pipeline and the pressure of the gas pipeline is thus designed. The two kinds of gas input mixers with different proportions are designed to ensure that the input of N_2 radical + C_3H_3 gas is smooth and the pressure of the C_3H_3 gas pipeline is positive to avoid the risk of air entering the pipeline.