The invention relates to an amorphous nickel-tungsten-phosphorus alloy electroplating solution applied to the electroplating of the pump barrel of an oil well pump, and a processing technology thereof. The amorphous nickel-tungsten-phosphorus alloy electroplating solution comprises a main salt, a buffering agent, a complexing agent, a conductive salt and deionized water, wherein the main salt is composed of 120-140 g/L of nickel sulfate, 10-20 g/L of sodium tungstate and 5-15 g/L of phosphorous acid; the buffering agent is boric acid, and has a concentration of 25-35 g/L; the complexing agentis citric acid and/or sodium citrate, and has a concentration of 20-30 g/L; and the conductive salt is sodium sulfate, and has a concentration of 20-30 g/L. An internal surface protection layer of thepump barrel adopts an amorphous nickel-tungsten-phosphorus alloy electroplating solution coating layer, and component proportions of the electroplating solution are adjusted to improve the neutral salt spray resistance, the acid and alkali corrosion resistance and the sulfide resistance of the protection layer; silicon carbide added as an additive improves the acid and alkali corrosion resistance and the wear resistance of the protection layer; and modification of the silicon carbide improves the bonding properties of the silicon carbide with metal components and a matrix material, improve the compactness of the structure and further improve the acid and alkali corrosion resistance and the wear resistance of the protection layer.