The generalized Reynolds equation is established considering cavitation mechanism based on modified Elrod method in theory. The cavitation characteristics of spiral oil wedge hydrodynamic bearings are investigated experimentally using transparent bearing and high-speed camera. The influence of speed of rotation and supply pressures on the shape of the cavitation and the location of the cavitation is analyzed, and the experimental results are compared with the modified Elrod calculation results. The results show that the cavitation of oil film is strip-shaped. With the increase in supply pressure, the rupture location of the oil film moves along the direction of rotation of the axis, the reformation location of the oil film moves along the opposite direction of rotation of the axis, the rupture area of the oil film decreases and the speed of rotation of the bearing increases when cavitation begins to occur; with the increase in speed of rotation, the reformation location of the oil film moves along the direction of rotation of the axis and the rupture area of the oil film increases. The experimental cavitation region is larger than the theoretical cavitation region; however, the theoretical results generally coincide with experimental results.