The invention relates to a heating panel of a wide channel plate type heat exchanger and a surface strengthening technique thereof. The heating panel with two plates which are combined together consists of a flat section at the two ends, a middle expanding section and an inclined radiating section, wherein, the inside of the middle expanding section is provided with a water flow channel, the outside surfaces of the flat section at the two ends and the inclined radiating section are provided with an erosion-resistance reinforced layer consisting of a layered high hardness alloy powder spraying layer and a high strength resin plugging layer. The surface strengthening technique adopts the supersonic spraying technique and the oxyacetylene spraying technique in the flame spraying technique; the erosion-resistance reinforced layer consisting of the layered high hardness alloy powder spraying layer and the high strength resin plugging layer is sprayed on the erosion working surface of the heating panel, thereby improving the surface hardness and the abrasion resistance of a stainless steel plate and contributing to improving the product quality of the heat exchanger, prolonging the service life and improving the working stability.