The invention provides a yawing angle calibrating method and device for a wind power unit. The yawing angle calibrating method comprises the steps that whether a switch turning signal is output by a cam switch of a rotary limiter in the yawing process of the wind power unit is monitored, the rotary limiter further comprises a gear which is in engaged linkage with teeth of a yawing shaft of the wind power unit, and the rotary transmission ratio of the gear to a cam set where the cam switch is located is fixed; and if the switch turning signal is monitored, the current yawing angle is set to be a preset yawing angle. By the adoption of the technical scheme, calibration of the yawing angle is achieved, so that yawing of the wind power unit is better controlled, the wind energy utilization rate is increased, and the power generation cost is reduced.