The invention provides a torque ripple suppression method for a direct-drive wind turbine generator, and relates to the technical field of wind power generation. The method comprises: for electromagnetic torque pulsation, using a harmonic voltage compensation suppression method: using a low-pass filter to extract a higher harmonic current component, calculating and superposing a harmonic voltage compensation value to a reference voltage, and the harmonic component being offset; for aerodynamic torque pulsation, using an independent variable pitch control method, establishing a weight coefficient distributor, calculating pitch angles corresponding to different blades through a mathematical model of weight coefficient distribution and acting on a variable pitch mechanism, and aerodynamic torque pulsation caused by pitch angle pulsation being reduced; and finally, on the basis of a harmonic voltage compensation method, arranging a rotating speed controller, the difference value between the actual rotating speed and the rated rotating speed of a generator serving as a deviation value and being introduced into the input end of the rotating speed controller, the output end of the rotating speed controller being a unified pitch angle reference value, and then achieving the cooperative suppression of pneumatic torque pulsation and electromagnetic torque pulsation in combination with anindependent variable pitch control method.