The invention provides a system and method for controlling smart household appliance. The system comprises a router, at least one smart household appliance, and at least one mobile communication device configured with an application program. The application program of the mobile communication device is connected to the smart household appliance in a LAN or WAN connection mode. The smart household appliance records the connection mode between each application program and the smart household appliance to generate a connection information. If the connection information indicates that there is not any application program connected to the smart household appliance in LAN connection mode, the application program of the mobile communication device will send a disable signal to the smart household appliance from a remote end to turn off the smart household appliance so that the energy consumption of the smart household appliance may be reduced when nobody is at home.