In this study, we studied the compression behavior of tungsten disilicide (WSi₂) to 35.5 GPa using synchrotron radiation X-ray diffraction with silicon oil as the pressure transmission medium in a diamond anvil at room temperature. WSi₂ did not undergo a structural phase transition within the pressure range studied. By fitting the volume data under different pressures, we obtained a bulk modulus of 289(3) GPa for WSi₂. In addition, we studied the bulk modulus, electronic band structure, and density of states of WSi₂ to the highest pressure of 40 GPa using density functional theory based on first-principles. The theoretical calculation shows that the bulk modulus of WSi₂ is 242 GPa. The theoretical calculation results indicate that WSi₂ exhibits both semimetallic and non-magnetic properties throughout the entire pressure range of 0–40 GPa.