It is a universal quest to produce molecular hydrogen (H₂) from sustainable green routes to diversify the heavy dependence of fossil fuels for energy consumption. Developing earth-abundant electrocatalysts for water electrolysis is a promising method to generate hydrogen via hydrogen evolution reaction (HER). In this work, we strategically promote electron transport and activate the basal planes of MoS₂ via a thermal hybridization with vertically-aligned hierarchical nickel phosphide Ni₅P₄-Ni₂P (denoted as MoS₂/Ni₅P₄-Ni₂P) for HER. The metallic-like Ni₅P₄-Ni₂P foam promotes electron transportation into the MoS₂ matrix by electron injection due to the difference of their Fermi levels. Moreover, MoS₂ basal planes are activated by Ni₅P₄-Ni₂P due to phosphorus doping effects, triggering additional actives sites and boosting the overall HER performances. Notably, the HER performance of MoS₂/Ni₅P₄-Ni₂P electrode only requires an overpotential of 96 mV to reach a geometric current density of −10 mA cm⁻² with relatively low Tafel slope of 74 mV dec⁻¹. The catalytic performances can last for at least 22 h at −10 mA cm⁻² without discernible degradation, indicating the extraordinary long-term operation stability. This work provides insights into the synergistic effects of a hybridized catalyst, which may potentially serve as a next-generation electrocatalyst for efficient water splitting.