Foamable rubber composition for tires as well as preparation method and application of foamable rubber composition

The invention provides a foamable rubber composition for tires as well as a preparation method and application thereof, and the foamable rubber composition is prepared from the following raw materials in parts by weight: 50-100 parts of medium halogenated butyl rubber, 0-50 parts of cis-1, 4-polyisoprene rubber, 5-50 parts of carbon black, 5-30 parts of a microsphere foaming agent, 5-20 parts of biological base oil, 1-10 parts of a hydrocarbon resin mixture, 1-5 parts of phenolic tackifying resin, 0-2 parts of an anti-aging agent and 3-7 parts of a vulcanizing agent. A microsphere foaming agent is adopted, the microsphere foaming agent is heated at 85-230 DEG C and then expands and foams to form a fine and uniform foam structure, and the microsphere foaming agent is added into a rubber formula to form a stable foaming effect, so that rubber is in a micro-foaming state, a layer of spongy rubber mixture is formed, and a spongy microporous structure is formed; and finally, noise generated in the running process