The distribution model of clutter and its parameter estimation have been the focus of radar signal processing. Compared with other distribution models, the radar clutter model in a state of subjection to the Pareto distribution is more dominant when it is fitted with the real clutter. As for clutters subject to the Pareto distribution, the range of effective estimation of the distributed parameters are restricted by adopting first two order moment or estimation method. Therefore, a novel estimation method based on the is proposed, and the effective estimation interval of the shape parameter is derived as (r,+∞). On the basis of such as these, an estimation method ofis further proposed by using the idea of negative order moment estimation, making the range of effective estimation of shape parameters extend to (0, +∞). The simulation results show that the estimation method of extends the range of effective estimation of shape parameters to the entire range. Compared with other estimators, the estimation method of runs faster and has better estimation performance in the interval (0, 1). And the application scope is more extensive in actual work.