Direct electrolysis of seawater to produce green hydrogen has attracted great attention. While the development of efficient and rapid manufacturing processes for high-performance electrodes, particularly for the oxygen evolution reaction (OER), remains trail. Here, we introduce an innovative approach to fabricate high-performance NiFe-based OER electrodes using an ultrafast and eco-friendly bidirectional pulse current (BPC) method, which remarkably shortens the production time to only 20 s. Our BPC method alternates oxidation and reduction currents within a single period, promoting the in-situ formation of porous NiFe(oxy)hydroxide nanosheets through dissolution/deposition processes. Moreover, this methodology creatively utilizes the “Cl− induced effect”, typically a hindrance in other electrochemical systems involving seawater or brine, to enhance the synthesis of electrodes from NaCl-based electrolyte devoid of additional Ni/Fe cations. The prepared NiFe-based electrode (NFF O-R 20 s) demonstrates remarkable OER catalytic activity, with optimal overpotentials (ηj) of 272, 308 and 367 mV at current densities (j) of 10, 100 and 1000 mA cm−2, respectively. Impressively, it maintains a low cell voltage of 1.59 V after enduring 1000 h of operation under the industrially current density of 300 mA cm−2, with a direct current energy consumption of 3.8 kWh Nm−3 H2 for overall alkaline seawater electrolysis. Our BPC preparation approach provides a promising path to construction high-catalytic activity, good-stability electrode, and low-energy consumption direct seawater electrolyzer.