Backlight module used in liquid crystal display device and control method of backlight module

The invention discloses a backlight module used in a liquid crystal display device and a control method of the backlight module. The backlight module comprises a light emitting unit and a power supply used for supplying power for the light emitting unit. The light emitting unit comprises a plurality of light sources connected in parallel, a plurality of switches corresponding to the light sources and a controller used for controlling the on-off state of each switch. Each light source is electrically connected with the power supply through one corresponding switch, and the switches are electrically connected with the controller. When the backlight module is started, the controller chooses to connect one of the switches in the following steps so as to turn on the light source corresponding to the connected switch. By means of the backlight module and the control method of the backlight module, service life of the backlight module can be prolonged.