The present invention provides a one-step urea synthesis system. In one embodiment, the system comprises a magnetic induction zone, a reaction chamber being disposed in and between the magnetic induction zone, a plurality of platforms being disposed inside the reaction chamber, catalyst/catalyst support micro-reactors grown on the bottom part of the plurality of platforms, a reactant gases inlet positioned at the bottom part of the reaction chamber for taking in reactant gases, wherein after the reactant gases enter the reaction chamber, they flow upward and reacts with the catalyst/catalyst support micro- reactors to form molten urea; and an outlet positioned at the bottom part of the reaction chamber for discharging the molten urea. The present invention also provides a method for one-step synthesis of urea.