Optimizing electronic structure and facilitating electron transfer modulation in electrocatalyst is the key to enhancing overall water splitting (OWS) performance. In this work, the heterogeneous transition metal phosphide Fe-CoPv/Ni2P@NF, consisting of cobalt phosphide and nickel phosphide, is obtained by simple iron salt infiltration and high-temperature phosphatisation. Due to the doping of iron-atom and the formation of phosphorus vacancies, the activity of metal atoms with higher valence states and spins is induced, and then highly active Fe/Co-O-Ni channels are generated in the dynamic water-splitting process, thereby increasing the exposure of reaction center and total electron transfer rate. The catalytic mechanism is attributed to reducing the potential barrier of phase remodeling and optimizing the intermediate binding strength, thus thoroughly stimulating OER and HER activities. The Fe-CoPv/Ni2P@NF shows superior performance, requiring only total voltages of 1.626 V (OWS) to reach 100 mA·cm−2 and maintaining ultra-high stability for 500 h, suggesting promising industrial applications.