Abstract: The signal acquisition systems based on Compressed Sensing is the major development orientation of wideband signal sampling. When it is used in communication reconnaissance or spectrum sensing, the received signal is a mixing of some narrow-band signals within wide range. Then the number of the mixed signals is the key to subsequent signal analysis. The paper proposed a source number estimation algorithm focus on the sparsity and distinctive features for modulated signal on the cyclic power level .The algorithm aimed at reconstructing the cyclic power spectrum by the improved OMP ,and the source number could be estimated with symmetry .Simulation results show it has a good performance of resolution when the SNR is -12dB.