Abstract: When airborne weather radar detects low-altitude wind shear in a non-uniform clutter environment, it will encounter inaccurate estimation of clutter covariance matrix, which will affect the correct estimation of wind speed. Regarding the issue above, this paper proposed a low-altitude wind shear wind speed estimation method based on direct data domin-generalized adjacent multiple beam (DDD-GMB) in non-uniform clutter environment. Firstly, the clutter covariance matrix was directly evaluated by range unit to be detected in a non-uniform clutter environment; Then, the space-time adjacent multi-beam and the time-domain adjacent Doppler channel are used to construct the space-time dimensionality reduction processor, which reduces the system freedom and the requirement of the number of training samples. Finally, constructing cost function estimated the wind speed.The simulation results showed that the proposed method can accurately estimate the wind speed in a non-uniform clutter environment.