Abstract:Design and implement an environment monitoring system at smart home based on APP, which can monitor the concentrations of CO、CO2、O3 and PM2.5 in real-time. In either the concentration of detected gas or PM2.5 exceeds the standard value, the system will immediately push the alarm message to users’ smart phones to alert users to start the appropriate procedures for indoor air purification treatment. System uses MQ7, MG811, MQ131 and GP2Y1010AU four kinds of gas detection sensors to detect indoor CO, CO2, O3 and PM2.5 concentrations, then sent the pollutant gas and PM2.5 concentration information to the backstage server through GPRS, APP on smart phone will obtain information on pollutant gas and PM2.5 concentration by querying the server through WIFI or 3G. Practice proves that precision of polluting gases and PM2.5 concentrations measured by this system reaches to 98%, and it presents change of concentrations to users with a curve, allowing users to be kept informed of the indoor environment status conveniently.