The invention discloses a mobile terminal for controlling a household appliance, a system and a method thereof. The mobile terminal obtains key codes for controlling the different functions of each household appliance by a learning process and stores the key codes. The method comprises the following steps: A. the mobile terminal determines to control the household appliance in a remote manner or in a short-range manner; if the remote control of the household appliance is required, step B is executed; otherwise, step C is executed; B. the key code corresponding to the function of the householdappliance to be controlled is sent to the household appliance to be controlled for executing the corresponding function; C. the key code corresponding to the function of the household appliance to becontrolled is encoded and sent to a network household appliance controller which receives and decodes the encoded key and sends the decoded key code to the household appliance to be controlled for executing the corresponding function. The mobile terminal, the system and the method can control the household appliance without modifying a receiving end of the household appliance, reduce the cost andare practicable.