In this study, the transfer matrix method is used to study the spin Hall effect of light on the surface of a functional photonic crystal with a defect layer. Through numerical calculations and analyses, we find that the transverse displacement of reflected light or transmitted light can be controlled by adjusting the polarization angle, incidence angle, period number of the functional photonic crystal, optical thickness of the defect layer, and circular frequency of the incident light. Numerical calculations reveal that 100-micron level transverse displacement can be achieved by adjusting the corresponding parameters. These results provide a theoretical reference for research into spin-based quantum communication and new optoelectronic devices.