The invention discloses a double-rotor through flat assembling movable blade through-flow type hydraulic generator which comprises an armature rotor mechanism, an excitation rotor mechanism, a first turning wheel mechanism, a second turning wheel mechanism, a guide vane mechanism, a water inlet tube and a draft tube. The armature rotor mechanism and the excitation rotor mechanism are coaxially arranged in parallel front and back and are hollow; the circumferential inner diameter part of the armature rotor mechanism is fixedly connected with the first turning wheel mechanism; the circumferential inner diameter part of the excitation rotor mechanism is fixedly connected with the second turning wheel mechanism; the front side of the first turning wheel mechanism is in butt joint with the water inlet tube through a rotary bearing; the guide vane mechanism is installed inside the water inlet tube; and the rear side of the second turning wheel mechanism is in butt joint with the draft tube through a rotary bearing. The double-rotor through flat assembling movable blade through-flow type hydraulic generator is free of ventilation systems or cooling water systems, high in power generation efficiency, good in universality, small in size, low in requirement for materials and long in service life, and a few consumables are needed.