The invention relates to a process for hydrogen production through carbon-containing slurry. The process for hydrogen production through the carbon-containing slurry is characterized by comprising thefollowing steps that the fresh carbon-containing slurry, a sulfuric acid aqueous solution containing ferric ions and a liquid phase from a first upper tower body of a first evaporation tower are mixed and then fed into a hydrothermal reactor for reaction, an obtained slurry oxidized liquid is conveyed into a first flashing tower for flashing, flashing gas is led into an upper tower body of the first flashing tower to exchange heat with the slurry oxidized liquid, the liquid phase is conveyed into a second evaporation tower, and a gas phase generated in a lower tower body of a second flashingtower enters an upper tower body of the second flashing tower for heat exchange; the liquid phase subjected to heat exchange exchanges heat with the gas phase in the lower tower body of the first flashing tower; supernate discharged and separated from the liquid phase is conveyed into an electrolyser for electrolytic hydrogen production; and the generated hydrogen is discharged, a generated electrolyte returns to the upper tower body of the second flashing tower to exchange heat with flashing steam, and after heat exchange, the electrolyte is conveyed to the upper tower body of the first flashing tower to heat exchange with the flashing steam of the lower tower body.