In order to obtain characteristics of along-wind self-excited forces of cables under extreme wind speeds, the flutter derivative with respect to along-wind damping of cable is derived according to the quasi-steady theory. Based on grid independency check for a fixed cable, suitable parameters and aerodynamic coefficients are determined as to insure quality of CFD simulation. For reduced wind speeds ranged from 53~1050, the flow fields around the along-wind forced vibration cable are simulated at Reynolds number of 5.18×105, as to identify flutter derivatives of P*1. The present results are in good agreement with values from the quasi-steady theory, which demonstrates the suitability of the present method. It also indicates that the flutter derivative of P*1 under extreme wind speeds can be determined through the quasi-steady theory. It is also found that under super high along-wind condition, the vortex-shedding forces dominate the total aerodynamic forces, and the forced vibration mode do not change the inherent vortex shedding frequency. It is recommended that the self-excited forces on cables are negligible under extremely high along wind action, and only vortex-shedding forces can be considered.