In order to study Interference Effect and drag coefficients of multi-bundled conductors under various azimuths, wind tunnel testing based on force measuring technique were employed. The drag coefficient of isolated conductor and circular cylinder with same diameter were investigated under various wind velocities and turbulence intensities. The drag coefficients of sub-conductor and total drag coefficients of multi-bundled conductor were obtained and their results are compared with those obtained from codes and other researchers. Finally, suggestive value of drag coefficients of multi-bundled conductors under various azimuth were given. Results show that the drag coefficient of the isolated conductor is 13 percent less than that of the circular cylinder with same diameter under high testing velocity, indicating that the twisted shape can reduce the drag coefficient of a circular cylinder. When two sub-conductors are in front-back arrangement, the drag coefficient of the back sub-conductor will decrease significantly, and the less distance between them, the more the drag coefficient decreases. The total drag coefficient of multi-bundled conductors will be smaller under certain azimuth in which the significant interference effect is took place. Suggestive value of drag coefficients of multi-bundled conductor with 23.94 mm in diameter and 400 mm in distance are given as follows. The drag coefficients of isolated conductor, two-bundled conductor, four-bundled conductor, six-bundled conductor and eight-bundled conductor are 1.02, 1.00, 0.97 and 0.93.