After the study of Matching Pursuit (MP) based signal sparse decomposition, analysis of structural property of the over-complete atom dictionary used in signal sparse decomposition is made, this paper creates frequency atom dictionary after seeking out centric position, dichotomy control of positional parameter based signal sparse decomposition algorithm is presented, applying to improved MP algorithm based on centric position parameter . The calculating speed of the algorithm in this paper increase by about 36 times compared with MP algorithm .This algorithm can reduce the computation complexity and improve the precision of sparse decomposition. Finally the simulation data processing verified that the proposed algorithm is effective and corrective.