The invention discloses a preparation method of superfine rhenium powder, taking high-purity ammonium rhenate as a raw material and comprising the following steps: heating the high-purity ammonium rhenate at an oxidizing atmosphere to decompose into high valence rhenium oxide Re2O7; and then reducing Re2O7 by H2 or CO to obtain superfine rhenium powder. The superfine rhenium powder obtained by the method of the invention has the advantages of low impurity content, sphere or sphere-like structure, even particle size distribution, high crystallinity, low oxygen content, good fluidity, high tap density and the like.