The purpose of the improved multi-sensor data fusion algorithm based on D-S evidence theory and criterion of the object evaluation is to solve the uncertainty problem of information processing in the portable indoor air monitoring and control system. Indoor air quality rating and evaluation are based on the researches from the data collected from indoor and the rating and evaluation results will trigger the activities of the Monitor. The experiment shows that the improved data fusion algorithm based on the D-S reasoning and the resulting evaluations are correct. The performances of the intelli...