The invention provides a glass fiber reinforced plastic cover plate used for a power cable tunnel and belongs to the field of mechanical components. The cover plate comprises a cover plate body which comprises at least two layers of glass fiber reinforced plastic, and an aluminum alloy sandwich layer or a layer of aluminum alloy sandwich plate is arranged between the two layers of glass fiber reinforced plastic; the aluminum alloy sandwich layer or the aluminum alloy sandwich plate has the functions of bearing loads and guaranteeing the rigidity of the cover plate body; the glass fiber reinforced plastic layers have the functions of reducing the weight of the cover plate and providing good insulation performance and good corrosion resistance; the aluminum alloy sandwich layer is a cellular sandwich layer; the aluminum alloy sandwich plate is an aluminum alloy cellular plate; the number of the glass fiber reinforced plastic layers is at least 10. According to the cover plate, the load bearing strength of the cover plate used for the power cable tunnel is improved through an aluminum alloy enhancement layer, the special requirement of the cover plate used for the power cable tunnel is met through the low weight, the good insulation performance and the excellent corrosion resistance of glass fiber reinforced plastic, and the requirements in actual work can be totally met.