According to the harm and influence of building air quality on human beings,a building air detecting system based on ZigBee wireless sensor network is designed,this system includes each module software and hardware design and can detect formaldehyde,benzene,sulfur dioxide,ammonia and nitrogen-oxygen compound and so on which are poisonous air harmful to human body,and data collection,processing,transmission,display and threshold warning are realized to provide safety information for households to avoid accidents.