For the problem of influence of background level on estimating target spatial azimuth distribution value, a method of MVDR spatial spectrum estimation based on Richardson-Lucy is proposed. The output results of MVDR spatial spectrum estimation method were deconvolution with point scattering function and Richardson-Lucy iterative method of image restoration, and the background level and its influence on estimating target spatial azimuth distribution value was reduced. The results of measured data show that, this method is a post-processing method, inherits the high resolution performance of MVDR spatial spectrum estimation method, has more sharp peak value, when signal to noise ratio is lower, has better performance of estimating target spatial azimuth distribution value.