The invention provides a yaw control method and device for a wind power generator set. The yaw control method comprises the following steps that real-time wind speed data of a wind power plant detected by a wind sensor is received; and when the the real-time wind speed data is determined to be smaller than the specific wind speed, the wind power generator set is controlled to carry out zero-pressure yaw, wherein the zero-pressure yaw indicates that the wind power generator set yaws under the condition that the pressure value of a hydraulic brake is zero or extremely small. According to the yawcontrol method and device for the wind power generator set, the pressure value of the hydraulic brake is set according to the wind speed, so that the wind generating set is subjected to the zero-pressure yaw control under the condition that the wind speed is smaller than the specific wind speed, the abrasion rate of a friction plate of the hydraulic brake is reduced, and the vibration noise of the wind power generator set is reduced.