To extend hybrid high-frequency shooting and bouncing rays-physical optics (SBR-PO) method to the modeling of electromagnetic (EM) scattering from an object in half-space, this paper focuses on addressing two key issues: 1) how to accurately obtain the induced electric currents on the object surface by taking into account the EM interactions between the object and half-space and 2) how to accurately calculate far-fields in half-space configuration. First, by introducing virtual interface of half-space, the proposed method avoids physically modeling the underlying ground, and only induced electric currents on the object are effectively taken into account in the SBR process. Second, the closed-form half-space Green's function is used to calculate scattered far-fields to avoid the time-consuming evaluation of the Sommerfeld integrals. The computational errors are only from the approximation of induced electric currents with the same level of the SBR-PO method for the solution of the free-space problem, so the proposed method is more accurate than the conventional SBR-PO technique. Besides, performing the proposed method on the graphics processing unit platform to further accelerate the ray-tracing process makes the method even more powerful to solve the extra-large-scale scattering problems in the half-space.