Abstract: In order to improve the separation efficiency of the swirl-vane separator, the swirl-vane steam separator with normal triangular drainage holes was built and studied by experimental and numerical methods using air-water mixture. The proportion of the separated water in each row of drainage holes and the effect of the drainage hole location on the separation performance were analyzed. The results show that when the superficial velocity of air is low (≤14.4 m/s), the proportion of the separated water in each row of drainage holes decreases at first and then increases with the increasing of height. When the superficial velocity of air is high(>14.4 m/s), the proportion of the separated water in each row of drainage holes decreases with the increasing of height. The study compares the separation efficiency of the swirl-vane separator when the drainage hole is located at 0.8D (the distance of the drainage hole from the swirl vane is 1 times of the inner diameter), 1.0D and 1.2D. When the superficial velocity of air is low (<12.9 m/s), the separation efficiency of the separator with the drainage hole at 1.2D is the highest. While the superficial velocity of air is high(≥12.9 m/s), the separation efficiency is the highest when the drainage hole is located at 0.8D.