The invention discloses a construction method for filling resin in a convex blocking platform of a plate-type ballastless-free rail. An infusion bag is adhered between the convex blocking platform and a rail plate by using an adhesive and infused with filling resin so that the convex blocking platform and the rail plate are favorably adhered. The construction method comprises the following steps of: preparing before infusion; stirring and mixing the infusion bag and the adhesive; coating the adhesive on the cylindrical surface of the convex blocking platform and the semi-circular curve of the rail plate; mounting a foam cushion; adhering the infusion bag; stirring and mixing the convex blocking platform with the resin; and infusing the resin, solidifying and subsequently processing. The filling resin constructed between the convex blocking platform and the rail plate has favorable adhesive force to concrete members, resists UV irradiation, hydrothermal aging and chemical corrosion, and has a certain elasticity and mechanical strength. The construction method is simple and convenient to operate, thereby being suitable for the mass construction of plate-type ballastless-free rails.