Purpose / Context - Improve indoor air quality. Methodology / Approach - Investigate the objectives of the study through subjective questionnaire survey and field test of the selected parameters. Results – According to the practical problems of the office building, the reasonable solution is put forward. Key Findings / Implications – The indoor thermal and humid environment, air quality and thermal comfort of human body were studied and analyzed in order to determine practical strategies for improvement program, aimed at addressing the problems existing in office buildings. Originality - Investigate the office building alone, make a concrete analysis of the factors influencing the quality of indoor air, propose an antidote against the disease of the office environment.