Abstract: Foam colloid is one of the effective means of fire prevention and control in mine. Whether the design of foam colloid triplet foamer is reasonable or not directly affects the actual performance of foam colloid. By means of VOF model to simulate the internal nitrogen foam generator and slurry mixing process, we analyzed the characteristics of foam generator tube flow, compared the mixing effects of structural parameters such as the number and position of nitrogen inlet pipe on foaming system, discussed the mixing effects of operating parameters such as slurry flow rate, nitrogen flow rate and position of regulating head on foaming system, and obtained the optimized structural and operating parameters of bubbler. The simulation results show that the number and position of nitrogen inlet tubes have a complex effect on the mixing effect of the foaming system, and the mixing effect is also related to the position of regulating head. Compared with the 6 inlet tubes in different positions, the average mixing degree of nitrogen with 9 inlet tubes can be increased by 1.7% to 10.4%, which is more conducive to the mixing and preparation of foam colloid in the foamer. In addition, based on the three-factor and five-level orthogonal test of slurry flow, nitrogen flow and adjusting head position in the foamer, the significance of slurry flow and nitrogen flow on the mixing effect of foaming system is 4.04 and 3.68 times that of the adjusting head position, respectively. The optimal working conditions of the foam colloid triplet foamer for fire prevention are the slurry flow rate of 20 m3/h, nitrogen flow rate of 1 200 m3/h, and the regulating head in the middle and rear position.