The invention discloses a nano-porous Fe-P-C material and a preparation method thereof, and applications in hydrogen production through water electrolysis, wherein a crystal strip of an alloy is prepared from the following components in percentage by mass: 22-64% of pure Fe, 19-41% of Fe3P and 17-37% of Fe3C. The preparation method comprises: carrying out mixing smelting on metal raw materials toobtain an alloy ingot, melting the alloy ingot, spraying out to obtain an alloy strip, and carrying out ultrasonic vacuum drying. According to the invention, a three-electrode system of an electrochemical workstation is used, a calomel electrode is used as a reference electrode, a platinum net is used as a counter electrode, a Fe-P-C alloy strip is used as a working electrode, an H2SO4 aqueous solution is used as an electrolytic solution, electrochemical corrosion is carried out through constant potential, the potential parameter is -0.1 V to -0.5 V, and the corrosion time is 600-1600 s. Compared with the noble metal catalysts on the market, the ano-porous Fe-P-C material of the invention has characteristics of high price advantage, high stability, simple preparation method, few process and good market industrialization prospect.