The invention relates to an aqueous-phasereforming system, in particular to a self-heating type methanol aqueous-phasereforming reaction system, which comprises a preheating chamber, a reforming chamber and an internal combustion engine and further comprises an evaporator and a heat exchange chamber; the evaporator, the preheating chamber, the reforming chamber and the heat exchange chamber are successively connected through a pipeline to form a first route; the heat exchange chamber, the evaporator and the internal combustion engine are successively connected through the pipeline to form a second route; the first route is communicated with the second route in the heat exchange chamber; and the internal combustion engine, the heat exchange chamber, the reforming chamber and the preheatingchamber are successively connected through the pipeline to form a tail gas route. The system utilizes high-temperature tail gas after hydrogen gas generated by methanol reforming reaction is burnt inthe internal combustion engine, reformed gas in the heat exchange chamber absorbs the heat of the high-temperature tail gas and releases the heat in the evaporator to heat and evaporate a methanol water solution at normal temperature, and enough heat is supplied for carrying out reforming reaction; and the high-temperature tail gas is cooled and then enters the reforming chamber, so that the temperature of the high-temperature tail gas is prevented from being too high to cause catalyst deactivation.