The invention provides a floating draught fan platform wave absorbing and roll stabilization power generation device and an active control method thereof. The floating draught fan platform wave absorbing and roll stabilization power generation device comprises three platform pile legs and supporting rods for being connected with the platform pile legs; a wave absorbing floater is arranged inside each platform pile leg, the upper end of each wave absorbing floater is provided with a stepping motor, a linear power generator rotor is connected to the output end of each stepping motor, and the lower end of each linear power generator rotor is provided with a thread; a buffer spring is matched with each thread of the corresponding linear power generator rotor through a thread seat, and the upper end of each buffer spring is connected with the inner top of the corresponding platform pile leg; the upper end of each platform pile leg is provided with the corresponding linear power generator rotor, and the upper ends of the linear power generator rotors sequentially penetrate through the buffer springs, the platform pile legs and linear power generator stators; and the outer surface of each platform pile leg is further provided with a bracket, and each bracket is provided with an incoming wave signal collecting device and an incoming wave signal processing device. The floating draught fan platform wave absorbing and roll stabilization power generation device can stay in the best wave absorbing and roll stabilization position all the time, and the efficiency of the wave absorbing and roll stabilization power generation device is greatly improved.