To address the issue of slow pollutant gas flow in the curves of high-altitude tunnels, this study investigates the influence of jet fan installation positions on ventilation efficiency. By using computational fluid dynamics software to establish a three-dimensional ventilation numerical model of jet fan at the bend, the influence of different jet fan placement on the pressure boost coefficient of the tunnel section was studied, and then the optimal fan placement was obtained by multi-factor analysis of variance and range analysis. The results show that: (1) The influence of jet deflection angle on the reduction coefficient is the greatest, while the influence of inner deviation distance on the reduction coefficient is the least. (2) When the jet deflection angle is 90°, the inner deviation distance is 1m to the inside and the axis deviation distance is 2 m to the left, the fan will increase the pressure on the section of the tunnel bend to the maximum. (3) When the fan deflection angle is too small, the jet will hit the tunnel wall in advance, causing a large loss of air flow kinetic energy. Through reasonable adjustment of the fan deflection angle, the jet can be fully developed and the overall air flow speed at the tunnel bend can be improved. (4) The jet fan can affect the sectional static pressure distribution within 100 m from the fan outlet; (5) Establish the functional relationship between altitude and pressure boost reduction correction coefficient: k=-0.075h+0.988. With the increase of altitude, the boost reduction coefficient of jet fan shows a decreasing trend, but it has little effect on the range of jet fan.