The present invention discloses a backlight module and an LCD device, comprising: a backplane and an LGP; the edge(s) of the LGP is provided with lug boss(es), each lug boss is provided with a positioning hole, and the backplane is provided with rivet(s) for matching with the positioning hole; a buffer structure is arranged between the rivet and the wall of the positioning hole. In the present invention, because the edge(s) of the LGP is provided with lug boss(es), each lug boss is provided with a positioning hole, the arrangement of the positioning hole does not influence the light guide area of the LGP; meanwhile, because a layer of buffer structure is arranged between the positioning hole and the rivet, the rupture of the part with concentrated stress in the positioning hole during collision is avoided. In addition, when the LGP is expanded with heat, the buffer structure can also avoid the extrusion damage caused by direct extrusion between the LGP and the rivet; when the LGP is contracted with cold, the gap between the LGP and the rivet is increased so that shake is easily caused. The gap between the LGP and the rivet is automatically filled by a buffer part through the elastic regulation of the buffer part. Thus, the shake collision of the LGP is avoided.