In order to study the effect of window opening angle on carbon monoxide concentration distribution in fire compartment, a numerical simulation method was used to investigate the influence of window opening angle on carbon monoxide concentration distribution in fire compartment.The results show that window opening angle can reduce the concentration of carbon monoxide on the window surface, the larger the angle, the lower the concentration at different heights; there is a critical angle between 15° and 45°, when the opening angle is greater than or equal to the critical angle, the reduction at the height of 0.15m on the window surface is almost the same; window opening angle is not the only factor to determine the reduction value of carbon monoxide concentration. In addition, the side effective projection area is also an influencing factor, and the effect of smoke exhaust in the front is better than that in the side.