The addition of transition metals, even in a trace amount, into heteroatom-doped carbon (M-N/C) is intensively investigated to further enhance oxygen reduction reaction (ORR) activity. However, the influence of metal decoration on the electrolysis of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), is seldom reported. In addition, it remains a big challenge to incorporate multiple dopants into the carbon framework. In this work, NiFe-decorated nitrogen, phosphorus, sulfur co-doped carbon nanoribbons (NiFe-N,P,S/C) derived from biomass is reported as a highly-active electrocatalyst for overall water splitting. Alfafa is chosen as the carbon source due to its abundance in C, N, P and S. The addition of NiFe bimetal during the one-step template-free synthesis is found to contribute to much longer and more robust carbon ribbons in contrast to the monometal-decorated or metal-free carbon (Ni-N,P,S/C,Fe-N,P,S/C, N,P,S/C).The pyrolysis temperature, and molar ratio between Ni and Fe are optimized. Ni0.75Fe0.25-N,P,S/C prepared at 900°C stands out from all the investigated materials and exbihtes a significantly enhanced OER, HER, as well as overall water splitting activity and stablity. The OER activity of Ni0.75Fe0.25-N,P,S/C exceeds that of the benchmark RuO2, and it also achieves a much better overall water splitting activity and stability in comparison to individual Pt/C and RuO2, making it one of the best carbon-based water splitting electrocatalysts.