A dome cover supporter is capable of improving durability of a product and extending a life span thereof by preventing roof panels from protruding upwardly by supporting a dome cover used in a storage tank, achieving resistance against a load by decreasing surface roughness, and extending a life span by preventing gaskets from being exposed to ultraviolet rays. The dome cover supporter includes a supporter including supporter main body formed in a vertical direction, a base formed in lower portion of the supporter main body to support the supporter main body against the ground, and horizontal extending pieces bent in an upper portion of the supporter main body to be extended; and a fixing member fastened to an upper portion of the supporter to maintain a seal by fixing and pressing roof panels.