Abstract: Ammonia is one of the common pollutants in the atmosphere, and the temperature has a significant impact on ammonia concentration detection results. In order to obtain the accurate concentration of ammonia, the influence of the temperature must be eliminated. The genetic algorithm was combined with differential optical absorption spectroscopy to explore the influence of temperature on ammonia concentration detection. The ammonia detection system at 296 K~328 K was developed based on ultraviolet differential optical absorption spectroscopy, and the compensated detection results were obtained by using genetic algorithm. The experimental results show that the temperature compensation model can effectively eliminate the non-linear influence of temperature on ammonia detection and improve the detection accuracy. The error of 44×10⁻⁶ ammonia detection results at 328 K is reduced by 26.97%. With the change of temperature, the linear correlation coefficients are above 0.998 16. For 6×10⁻⁶ ammonia, the detection limit of the system is 0.198×10⁻⁶ and 0.278×10⁻⁶, respectively, before and after temperature compensation.