Two-dimensional anisotropic materials have been widely concerned by researchers because of their great application potential in the field of polarized detector devices and optical elements, which is a very important and popular research direction at present. As a IV-V two-dimensional material, silicon phosphide (SiP) has obvious in-plane anisotropy and exhibits excellent optical and electrical anisotropy properties. Herein, the optical anisotropy of SiP is studied by spectrometric ellipsometry measurements and polarization-resolved optical microscopy, and its electrical anisotropy is tested by SiP-based field-effect transistor. In addition, the normal and anisotropic photoelectric performance of SiP is shown by fabricating a photodetector and measuring it. In various measurements, SiP exhibits obvious anisotropy and good photoelectric performance. This work provides basic optical, electrical, and photoelectric performance information of SiP, and lays a foundation for further study of SiP and applications of SiP-based devices.