The invention relates to a millisecond hydrogen-producing method. The method comprises: in a micro-channel reactor, catalyzing methane and water vapor for a reforming reaction by a Ni-based catalyst plate, and finishing the hydrogen-producing process in millisecond stay time. The micro-channel reactor is formed by inserting catalyst plates into the reactor to form micro-channels and assembling each micro-channel, and the height of each micro-channel is less than 2 mm. The Ni-based catalyst plate is prepared by taking FeCrAl-Al2O3 composite basic plate as a support, coating with an AlOOH sol and immersing with Ni. The Ni load capacity on the Ni-based catalyst plate is according to NiO accounting for 5-50% by mass of the total of NiO and Al2O3. The millisecond hydrogen-producing method has the advantages of being small in equipment volume, low in cost, high in production capacity and high in efficiency, and is extremely suitable for distributed hydrogen production.