Efficient separation and utilization of photogenerated electrons as well as holes play decisive roles in boosting photocatalytic hydrogen evolution reaction (HER). To reach this goal, we designed carbon black (CB) and Co1.4Ni0.6P as dual cocatalysts co-modified graphitic carbon nitride for efficient and stable photocatalytic HER. This resulting ternary photocatalyst was synthesized by sonochemical loading and high-temperature phosphatizing. Impressively, the maximum photocatalytic hydrogen-production rate for the ternary photocatalysts could reach 405 mu molh(-1) g(-1) , which was 810,2 and 1.7 times higher than those of pure g-C3N4 (0.5 mu molh(-1) g(-1)), g-C3N4-Co1.4Ni0.6P (195 mu molh(-1)g(-1)) and g-C3N4-1% Pt (230 mu molh(-1)g(-1)), respectively. Through the test analysis, the enhanced hydrogen-evolution performance was attributed to the synergetic effect between the metallic CB and the low-cost Co1.4Ni0.6P cocatalyst. More interestingly, the Co1.4Ni0.6P cocatalyst could not only decrease the recombination of photogenerated electrons and holes, but also boost absorption in the visible region and the hydrogen-evolution kinetics. Furthermore, the formation of Schottky heterojunctions between metallic CB and g-C3N4 nanosheets could further accelerate the separation and transfer of photogenerated electrons. This work provides a simple and facile strategy to rationally design highly efficient photocatalyst using low-cost nano-carbon materials and high-activity metal phosphide.