Quantitative Phase Microscopy (QPM), which combines phase imaging and optical microscopy, has been acting as a fast, non-destructive, and high-resolution methodology to measure the 3D morphology of reflective samples, as well as the inner structure or the refractive index of transparent samples. Similar to other diffraction-limited imaging systems, QPM suffers from the contradiction between spatial resolution and field of view (FOV). Therefore, how to achieve high spatial resolution in a large FOV has attracted a lot of attentions in the field of optical microscopy. In recent years, people utilized off-axis illumination, speckle illumination, structural illumination, and sub-pixel technology to synthesize a larger numerical aperture (SNA), and consequently enhanced the resolution of QPM. The resolution enhancement technologies of QPM were reviewed in this paper. The advantages and limitations of different methods were analyzed.