Consider the inverse acoustic scattering of time-harmonic point sources by a piecewise homogeneous medium with a buried object inside. Part of boundary of the piecewise homogeneous medium is assumed to be known, which allows us to construct an auxiliary Green’s function. Based on the Green’s function and an outgoing-to-incoming operator, we then propose the factorization method to simultaneously reconstruct both the rest of boundary of the piecewise homogeneous medium and the buried object inside from near-field data. Numerical experiments are presented to demonstrate the effectiveness of our inversion algorithm.