Large eddy simulation (LES) is utilized to simulate flow around a circular cylinder with/without an upper rivulet at Reynolds number 70000. Mean and fluctuating wind pressure coefficients on the artificial upper rivulet and the circular cylinder are obtained. The flow field and the vorticity magnitude in the wake flow zone of the cable model with rivulet at different positions were also investigated. It is found that a small vortex occur near the back of rivulet, when it locates in some particular positions, that might be the reason aerodynamic forces changing dramatically. These results lay foundation for the research on regulation about the influence of rivulet size and shape on cable aerodynamic in future.