Wide-gap defects repair of Mar-M247 superalloy was investigated by utilizing powder metallurgy. New interlayer alloy withrelatively high content of B and Zr was designed based on the isothermal solidification principle. The interlayer alloy ischaracterized by relative low melting temperature (1100 °C), and the contact angle of interlayer on the Mar-M247 substrateis ~ 70º. Based on the thermodynamic calculation results, the mixture powders with 80 wt% substrate powder and 20 wt%interlayer alloy powder was used as a filler to repair the wide gap with width of 2 mm. After repaired at 1230 °C for 2 h, nearfullydense gap was obtained. MC-type carbides, MB2-type boride, M3B2-type boride and Ni5(Zr,Hf)-type intermetallic wereobserved in the liquid zone. After post-weld heat treatment, the block borides, chain carbides and eutectic are successfullyremoved, and the tensile strength of the bonding zone is close to that of the Mar-M247 superalloy.