The invention discloses magnesium aluminate spinel powder, a preparation method and application to preparation of a refractory material. The magnesium aluminate spinel powder is prepared from the following preparation raw materials: magnesium oxide and boehmite. The preparation method is a sintering method; a mass ratio of magnesium oxide to the boehmite is 1:(2.98 to 3.72). During a preparation process, magnesium aluminate spinel grows through a template method mechanism by taking the boehmite as a template. The preparation method has the advantages that the product purity is high, the equipment is simple, the technology operability is strong, and large-scale production can be easily realized.