Abstract: Longitudinal ribs are set as one of the aerodynamic suppression measures for stay cable to suppress the wind-rain vibrations, which can suppress the vibration by preventing the formation of the waterline. However, in practical engineering, it is found that in addition to wind-rain vibration, vortex-induced vibration often occurs in stay cables at low wind speed, which is likely to cause fatigue damage of structures. Whether the longitudinal ribs used to suppress wind-rain vibration can suppress vortex-induced vibration and how the aerodynamic characteristics of stay cables with additional longitudinal ribs change are very concerned in wind-resistant design. The changes of aerodynamic force and vortex-induced vibration characteristics of stay cables with 2, 3, 4, 6, 8 and 12 ribs at different wind attack angles (The angle between the direction of the wind and the horizontal direction of the model) were studied by wind tunnel test. The results show that for the circumferential average wind pressure distribution, the Reynolds number corresponding to the asymmetric distribution of the circumferential average wind pressure coefficient decreases under a small wind attack angle in the stay cables with two ribs and three ribs. Under the large wind attack angle, similar phenomenon are observed in the stay cables with 4, 6, 8 and 12 ribs, and the increase of Reynolds number has no effect on the circumferential average wind pressure distribution. For the average drag coefficient, the phenomena that the average drag coefficient decreases with the increase of Reynolds number occurs first in the stay cables with two ribs and three ribs under a small wind attack angle. Under the large wind attack angle, the increase of Reynolds number has no effect on the average drag coefficient, which is consistent with the cases of 4, 6, 8 and 12 ribs. For vortex-induced vibration, compared with the cable without ribs, the ribs of the cables with 2 ribs and 3 ribs can reduce the maximum amplitude. For the cables with 4, 6 and 8 ribs, the change of the maximum amplitude is not obvious. The cable with 12 ribs has the best suppression effect at 15° wind attack angle, which is reduced by about 35%. Therefore, in practical engineering applications, the vibration suppression effect and aerodynamic force should be considered comprehensively.