Fourier　ptychography　is　a　new　type　of　synthetic　aperture　imaging　technique　based　on　phase　retrieval　method　which　can　improve　microscopeic　imaging　performance　beyond　the　diffraction　limit　of　the　employed　optical　components　by　illuminating　the　object　with　oblique　waves　of　different　incident　angles　where　the　field　of　view　remains　unchanged.　illumination　angle　and　the　overlap　rate　of　spectrum　will　have　a　certain　impact　on　the　quality　of　reconstruction.　In　this　paper,　we　study　the　effects　of　illumination　angle　and　spectral　overlap　rate　on　the　image　quality　of　Fourier　ptychography.　The　simulation　results　show　that　increasing　the　illumination　angle　and　spectral　overlap　can　improve　the　resolution,　but　there　is　a　threshold　for　the　key　parameters　of　spectral　overlap　rate.　The　convergence　rate　decreases　when　the　overlap　rate　exceeds　70%,　and　the　reconstruction　process　is　more　time-consuming　due　to　the　high　overlap　rate.　However　the　results　of　proposed　study　shows　that　an　overlap　of　60%　is　the　optimal　choice　to　acquire　a　high-quality　recovery　with　high　speed.