The kindergartens, characterized by large scale and daytime usage, possess evident typicality and necessity for the application of low cost solar energy. As the main learning place for school-age children, the indoor air quality of kindergarten has significant influence on children’s physical health. To verify the effects of a new flat plate solar air collector system (SACS) with metallic heating panels on the improvement of indoor living environment in kindergarten buildings, the indoor temperature, humidity and air quality in kindergarten were tested and investigated in this paper. Two indoor activity units with the same conditions in kindergarten of Shandong Jianzhu University, were selected as the test rooms. The working conditions of solar air collector in these two test rooms were taken as the reference variable. The systematic monitoring and analysis of air quality parameters such as temperature, humidity and carbon dioxide concentration in 12 reasonably distributed sampling positions were carried out during the continuous five days. The results show that the SACS possesses evident auxiliary heating function for indoor air. The maximum value of the average temperature raise nearly reaches 15%. The preheated air near the air outlet exhibits 10°C higher temperature than outdoor air. Besides, the system leads to slightly lower indoor humidity. In addition, the value of indoor CO2 concentration significantly decreases up to 800 ppm due to the filtration of the system. Instead of air conditioning to a certain extent during transition seasons, this system can effectively reduce the building energy consumption. It can provide children a more healthy and comfortable indoor air environment through the effective use of green solar energy. The research results in this paper can provide important reference for the wide application of solar air collector system in the special building environment of kindergartens.