This paper introduces a polarization-based single-frame wavefront reconstruction method using a compact and stable shear interferometry structure for real-time measurement of large aberration wavefronts. This approach overcomes the need for multiple images in traditional lateral shear interferometry, allowing real-time reconstruction of large aberration samples. The method is theoretically supported by simulations based on an infinite conjugate model, and computational reconstruction of large aberration wavefront samples confirms the algorithm's feasibility. A dual-plane mirror tunable shear interferometry structure, combined with polarization devices, is experimentally validated using a resolution target, achieving real-time fringe separation and wavefront reconstruction. The results show high accuracy with a root mean square error of 60 nm and improved runtime of 0.11 s. The proposed design and algorithm eliminate the need for multiple image reconstruction, simplify lateral shear interferometry, improve detection efficiency of three-dimensional macro and micro samples, and have potential applications in optical quantitative coherent interferometric measurement.