The present disclosure provides a split cooling apparatus for an internal combustion engine, the apparatus including: a base inserted into a water jacket of a cylinder block, the base surrounding an outside of a cylinder along a shape of the cylinder; an insertion groove formed on the base by being depressed into an inner surface of the base; and a sealing member inserted into the insertion groove, wherein when a temperature of cooling water supplied into the water jacket reaches a preset temperature or higher, the sealing member expands so as to close a flow passage between the base and the cylinder, thereby increasing flow resistance of the cooling water and thus reducing a heat transfer rate of the cylinder.