Abstract: The aerodynamic interference betweencylinders is a topic of great theoretical and practical significance. Though some windtunnel tests related to wind pressure distribution on cylinders complex havebeen carried out at home and abroad, only cylinders of equal-diameter and Reynolds number below 10^5 are considered. However,actual engineering structures are often immersed in wind flows of high Reynoldsnumber. This paper studies the time-averaged flow at high Reynolds number (Re=4.5\times10^5) around two cylinders of unequal-diameter, combined intandem, side-by-side and in staggered styles, which is simulated by numericalmethods, for various spacings and wind directions.The time-averaged drag, lift and resultant wind forces on twocylinders are obtained and analyzed. Which may serve as a reference forwind-resistant design for similar structures.