By replacing the single-photon detector in a HBT (Hanbury-Brown-Twiss) experiment by a pair of homodyne detectors, we constructe a modified-HBT interferometer. We introduce the principle and procedure for the measurement of the second-order correlation function of light field based on the modified-HBT interferometer, and maily discuss the substraction of dark noises in the process. Based on the theoretical analysis, we realize the measurement of the second-order correlation function of displaced squeezed light output from an optical parametric osciallator and the characterization of photon statistics features through the simultaneous record and statistics of the quadrature information collected by the above interferometer for two spatially separated mode of light field. For amplitude squeezed light, its second-order correlation functional value is less than 1 under a specific displacement, indicating photon anti-bunching. In contrast, for phase squeezed light, the second-order correlation functional value is always greater than 1, indicating photon bunching. The properties of photon statistics for displaced squeezed light are explained from a viewpoint of two-photon interference, which can provide a reference for understanding the photon statistics features of squeezed light.