According to statistics, the proportion of indoor activities in today’s society has reached more than 70%. Indoor air quality has become a major factor affecting the people’s quality of life and health. In order to realize the detection and monitoring of diversified indoor air pollutants, this paper proposes one research idea of detecting indoor pollutants based on numerical simulation method. The visualization program ITES2.0 was used as the numerical simulation software to simulate and evaluate the indoor indexes such as formaldehyde, carbon dioxide, temperature and airflow velocity etc. in the building. Besides, the two schemes of the actual instrumental measurement and the subjective evaluation questionnaire were set up respectively for comparison. By taking one indoor office in Changsha city as the example, the numerical simulation was conducted to make comparation and validation of pollutant concentrations between instrument measurement and subjective evaluation. The experimental comparison results show that the relative error of the average index values between the numerical simulation results and the actual measured values at each detection point is 10%, which is consistent with the subjective evaluation of the indoor air quality grade.