Abstract: The dynamic heading measurement and estimation method have important significance in positioning and control of navigation for agricultural machinery. The method of orientation dynamic measurement and evaluation was studied in the paper. HMR3000 electronic compass and ADXRS300 micromechanical gyroscope were fixed on Kubata rice transplanter to measure its dynamic orientation. Windows evaluation algorithm based on covariance function was proposed to evaluate the measure variance of electronic compass and micromechanical gyroscope. Based on measurement error, adaptive weighted fusion algorithm was used to integrate the data from two kinds of sensors to evaluate the dynamic orientation of rice transplanter. The experimental result shows that the algorithm is suitable for testing course leading under dynamic condition of agricultural machinery, and has strong anti-interference ability to smooth and filter the measurement noise. The algorithm can provide more precise and reliable orientation data and has better economy.