To suppress ground clutter and barrage noise jamming for airborne radar effectively and efficiently, a cascaded method using the sparse representation technique is proposed. Based on the sparsity of jamming in the spatial domain, the jamming subspace is first estimated using the orthogonal matching pursuit algorithm with only one snapshot. Then, the jamming is rejected by projecting the received signal on the orthogonal complement subspace of the jamming. Lastly, reduced‐dimension space‐time adaptive processing algorithms are utilised directly to suppress clutter. Simulation results demonstrate that the novel method could achieve great performance as well as a significant saving of computation and training samples.