In order to reduce the probability of vibration and improve the service life of cable-stayed. A new kind of cable-stayed casing appearance is presented . Firstly, the paper preliminary designs a new kind of casing appearance called modeled water-drop, based on aerodynamics. And through simulation with CFD, also compared it with the simulation result of modeled torpedo appearance and then get a result that the new appearance can reduce the generating probability of cable-stayed tail vortex. It can reduce sharply vibration and improve the stability of cable-stayed effectively. Finally, it conducts parameters optimization of the initial imitated water-drop aerodynamic appearance by Genetic Algorithm of Matlab , and gets the optimized appearance. The results show that the optimized appearance is more stability of vibration and more ideal of Shock absorption effect.