Snake Island is located seven nautical miles to the west of Dadianzi Xihuju in the Shuangdao Sub-District of Lushunkou, Dalian, and has an area of 0.8 square kilometers. Facing both the Yellow Sea and Bohai Sea, the preservation area starts at the Laotie Mountain in the south and goes to the Shuangdao Sub-District to the north, forming a rectangular area 25 kilometers long from north to south and 7 kilometers wide from east to west. The total area is 17,073 hectares, with a core area of 4,000 hectares. 

Snake Island is a lonely island next to the mainland. The highest point of its hill is 216.9 meters. It is a monotonous cuesta, which is high on the west and low on the east. Its terrain types include sea erosion terrain, marine terrain, gravitational accumulation terrain, soil, and brown soil. The vegetation is made up of mostly secondary broad-leaved deciduous forest, with trees and shrubs sprouting grass in between. Eagles and rats are the natural enemies of the vipers on Snake Island. It is of a cold temperate monsoon climate. The four seasons are clearly defined but with no abrupt changes. The summer is not too hot, and the winter is not too cold. Fresh water is scarce, mostly provided through manually-stored rainwater.