The hop timing estimates derived from existing methods are coarse and unreliable, therefore, a novel method for estimating hop timing for frequency-hopping signals precisely was proposed based on an improved orthogonal matching pursuit algorithm. The sparse representation model for hop timing estimation was established according to the principle of frequency-hopping signals. Then, the improved orthogonal matching pursuit algorithm was used to solute the model and get hop timing finally. The theoretical analysis and simulation results verified that the method is capable of obtaining precise hop timing, and is better than current methods.