The invention discloses a carborundum based fingered Schottky contact nuclear battery and a fabricating method thereof, mainly solving the problems of difficult fabrication process of a carborundum pn nodule battery and low efficiency of a Schottky nodule battery in the prior art. The carborundum based fingered Schottky contact nuclear battery sequentially comprises a bonding layer (1), a radioactive isotope source layer (3), a fingered semitransparent Schottky contact layer (2), an n type SiC epitaxial layer (5) with doping concentration of 5*1015-5*1015cm<-3>, an n type SiC substrate (6) with doping concentration of 5*1017-5*1018cm<-3> and an ohmic contact electrode (7), wherein an SiO2 passivation layer (4) surrounds the radioactive isotope source layer. The fingered semitransparent Schottky contact layer (2) comprises one horizontal finger strip and a plurality of vertical finger strips, wherein all the vertical finger strips are positioned at one side of the horizontal finger strip, and the radioactive isotope source layer (3) is positioned on the epitaxial layer (5) between the vertical finger strips and the horizontal finger strip. The invention has the advantages of littleenergy loss and high energy conversion efficiency, and can be used as an on-chip power supply of an MEMS (Micro-electromechanical System), a cardiac pacemaker power supply and a mobile phone standby power supply.