The invention relates to a preparing method for a high-toughness and heat resisting TiC/TiN steel bond hard alloy. The preparing method is characterized that one of TiO2 powder, TiH2 powder and Ti powder and colloidal graphite powder are prepared according to the C/Ti atomic ratio of 0.7-1.1, one of the TiO2 powder, the TiH2 powder and the Ti powder and urea ((NH2)2CO) are prepared according to the N/Ti atomic ratio of 0.4-1.1, and accordingly in-situ synthesized TiN mixed powder is prepared; ferro-molybdenum powder, ferro-vanadium powder, ferro-chromium powder, ferro-manganese powder, ferro-silicon powder, iron powder, ferro-boron powder, nickel powder, colloidal graphite and rare earth raw materials are prepared according to the needed proportion for the bonding phase metal chemical component mass ratio to be arranged into a steel ball mill, absolute ethyl alcohol serving as a medium and PVA are added, after ball milling and slurry drying, pressing forming is conducted, and the steel bond alloy is obtained through sintering. The in-situ reaction synthesizing technology and the liquid phase sintering technology are combined, reinforced particles are fine in size, the surfaces are free of sharp corners, base body interface bonding is good, and the interface is clean. Through the method for preparing the steel bond alloy, the comprehensive mechanical performance of the alloy can be improved, cost is low, and the technology is easy and convenient to conduct.