This disclosure provides a backlight comprising an optical component and a frame that comprises a receiving part, said optical component being disposed in said receiving part, said optical component comprising a reflective sheet for reflecting light towards a light exit of the backlight, said reflective sheet comprising a reflective sheet body and a lug arranged on at least one side of the reflective sheet body, said lug protruding outwardly of the reflective sheet body along a length or a width direction of the reflective sheet body, a clamp slot corresponding to the lug being arranged on a side wall of said receiving part, said lug being arranged within the clamp slot. Correspondingly, this disclosure provides also a liquid crystal module and a display device. Compared with the prior art, during repair and maintenance, the backlight of this disclosure avoids the damage to the reflective sheet caused by tearing double-sided adhesive and avoids waste of the double-sided adhesive, thereby reducing the manufacturing cost.