Provided is a preparation method of an energy-saving composite refractory material. The method includes the steps that a, magnesium oxide and calcium oxide are mingled, clear water is used for removing impurities in magnesium oxide and calcium oxide, and magnetic separation for removing iron is performed, then a pulverizer is adopted for smashing to obtain a first mixture after drying; b, fine serpentine powder, silicon carbide and waste tail slags are blended and disposed by a ball mill in a ball-milling mode to obtain a second mixture; c, the second mixture is added with a bonding agent, and stirred and mixed with a plasticizer after being stirred evenly to obtain a third mixture; d, the third mixture is disposed by calcination and drying to complete the whole process. Refractory materials prepared by the preparation method have the advantage of great thermal shock resistance, and meanwhile, since the silicon carbide generates a silicon dioxide layer film under a high temperature in a refractory material layer, the slags are prevented from soaking into the refractory material layer, and the corrosion caused on the refractory material layer by the slags is restrained.