A special mold for a pseudo alloy prefabricated member is characterized in that the mold comprises a bottom mold body, a lower mold body, an inner mold body, cushion blocks, an outer mold body and an upper mold body, the hollow lower mold body is arranged on the upper end face of the bottom mold body, and the inner mold body is located in the middle of the lower mold body and extends out of the lower mold body upwards; the cushion blocks are arranged on the upper end face of the bottom mold body; the outer mold body is located on the cushion blocks, is arranged on the periphery of the lower mold body in a sleeving mode, and extends out of the lower mold body upwards; the hollow upper mold body is arranged on the periphery of the inner mold body in a sleeving mode and located on the lower mold body; the upper end face of the lower mold body, the outer side face of the inner mold body, the inner side face of the outer mold body and the lower end face of the upper mold body form an annular forming cavity of the prefabricated member. The invention further discloses a pseudo alloy prefabricated member preparing method. Compared with the prior art, the pseudo alloy prefabricated member special mold and the pseudo alloy prefabricated member preparing method have the advantages that the overall manufacturing process is simple and convenient, the material utilization rate is high, manufacturing efficiency is high, and cost is low.