A method for controlling a floating body wind power electricity generation device wherein a wind power generator is erected on a floating body, said method being equipped with a pitch angle increase step, wherein the pitch angle of the blades of the wind power generator is increased so as to apply aerodynamic braking force to the rotor of the wind power generator when the wind power generator is stopped. In the pitch angle increase step, a first rate of change of the pitch angle of the blades during a first period of movement, wherein the wind power generator is inclined more to the upwind side than the vertical direction by the rocking of the floating body, is made less than a second rate of change of the pitch angle of the blades during a second period of movement, wherein the wind power generator is inclined more to the downwind side than the vertical direction by the rocking of the floating body.