The invention discloses an extrusion-type backing plate for a photovoltaic cell. The backing plate comprises an upper surface layer, a core layer and a lower surface layer, wherein the upper surface layer is composed of polyamide resin, filler, a flame retardant and additives, the core layer is composed of polypropylene resin and grafted polyethylene modified polyamide resin, filler, flame retardant and additives, the lower surface layer is composed of polyamide resin, flame retardant, a coupling agent and additives, the flame retardant is composed of a nanoscale inorganic flame retardant subjected to surface treatment and red phosphorus, the nanoscale inorganic flame retardant is selected from aluminum hydroxide and/or magnesium hydroxide of 10-100 nm, and a used surface treating agent is ethylene-based polyhedral oligomeric silsesquioxane of 1-5 nm. The extrusion-type backing plate is good in flame-retardant effect which reaches the A level through combustion tests, and it can be guaranteed that the flame retardant has no influence on the mechanical property, aging-resistant property, waterproof property, insulating property and the like of the extrusion-type backing plate.