Yaw calibration method and system for wind turbine

The disclosure proposes a yaw calibration method and system for a wind turbine. The calibration method includes: establishing a cylindrical coordinate graph of wind resource distribution based on historical wind farm operation data, to determine a wind direction interval of main inflow wind conditions of a wind farm; calculating an effective value of active power of each wind speed sub-interval, and obtaining a fitted power curve of each refined interval through curve fitting; and setting an angle between a central axis of a refined interval for a fitted power curve corresponding to a calibration curve in each wind speed range and a central axis of the to-be-calibrated wind direction interval as a yaw error calibration value in the wind speed range, to establish a wind speed-yaw error calibration value lookup table; and determining a yaw error calibration value under a current wind direction and a current wind.