Abstract: Estimating unknown wall parameters is typically important for the application of through-the-wall radar (TWR). The time-delay-only estimation (TDOE) method is able to efficiently retrieve the constitutive parameters of the homogeneous wall under test. For the TDOE method, the estimation accuracy of time delays of wall reflection signals directly affects the accuracy of wall parameter estimation. In this paper, we propose a sparse recovery method for estimation of wall parameters, which exploits the sparsity of the wall reflection signals and utilizes the orthogonal matching pursuit (OMP) algorithm to retrieve the time delay estimation for each bistatic antenna separation. Then the TDOE method with the hybrid bistatic-monostatic measurement configuration is applied to obtain the relative permittivity, thickness and conductivity of the wall. Numerical simulation and experimental results have shown that the proposed estimation method is capable of providing the estimation of wall parameters with more accuracy and robustness.