The invention discloses a rear-earth aluminum, silicom and calcium ferroalloy and a preparation method of the rear-earth aluminum, silicom and calcium ferroalloy and belongs to the technical field of a steel-making deoxidizer. The rear-earth aluminum, silicom and calcium ferroalloy comprises the following components in percentage by weight: 40 to 70 percent of aluminum, 1 to 4 percent of silicon, 1 to 10 percent of rear earth, 5 to 10 percent of calcium, smaller than or equal to 0.2 percent of carbon, smaller than or equal to 0.03 percent of sulfur, smaller than or equal to 0.03 percent of phosphor, smaller than 1 percent of inevitable impurity elements, and the balance of iron. Pure aluminum ingot, rear earth, high-quality silicon iron, metal calcium and low-carbon and high-quality waste steel are prepared into a finished alloy meeting requirements through a two-step melting process in an induction furnace. The alloy has the advantages that Mn element is not contained, so that a low-Mn steel variety can be produced; the alloy simultaneously contains Si and Al, so that a better complex deoxidation effect to molten steel is achieved when the alloy is added in a steel-making process; inclusion modification and removal effects are enhanced by relatively higher Ca content and certain RE; in an alloy preparation process, after the waste steel is molten into molten steel, at first, a Si alloy is added to deoxidize, the yield of Al is obviously improved, and the alloy cleanness is also improved.