The embodiment of the invention provides a backlight module, a display device and a use method of the backlight module and relates to the field of liquid crystal display. The backlight module can reduce view crosstalk of the left eye and the right eye and improve the 3D watching effect. The backlight module comprises a back panel and a diffusion plate. At least one LED lamp strip is arranged on the back plane. The backlight module further comprises at least one reflecting sheet and a control unit. The reflecting sheet is located between a backlight source and the diffusion plate. The control unit is used for controlling opening of the reflecting sheet corresponding to the first LED lamp strip when the first LED lamp strip is turned on. The backlight module and the display device are applied to the liquid crystal display field.