The invention discloses a Pm-147 silicon carbide graded N-region isotope battery and a manufacturing method thereof. The isotope battery structurally comprises, from bottom to top, an N-type ohmic contact electrode, an N-type highly-doped SiC substrate, a N-type SiC epitaxial layer, and a N-type SiC epitaxial layer; a P-type SiC ohmic contact doped region is formed at the upper part of the N-typeSiC epitaxial layer by adopting ion implantation; a P-type ohmic contact electrode is arranged in the center of the top of the P-type SiC ohmic contact doped region, a SiO2 passivation layer is arranged in the region of the top of the P-type SiC ohmic contact doped region without the P-type ohmic contact electrode; and a Pm-147 radioactive isotope source is arranged above the SiO2 passivation layer. The design is novel and reasonable, the collection problem of ionization energy deposition of the Pm-147 in the deep position of the material can be effectively solved, and the output power and theenergy conversion efficiency of the isotope battery are effectively improved.