The invention discloses a rubber foam material and a manufacturing method thereof. A rubber base material, a heat conducting filler, a radiation crosslinking sensitizing agent, an anti-aging system, a plasticizer, a vulcanization system and a foaming system are used as raw materials, mixing, piece cutting and gamma ray radiation preprocessing are performed, and then vulcanization, foaming and mold stripping are performed to obtain the rubber foam material. According to the preparation method, a film preprocessed by gamma ray radiation preprocessing has the certain pre-crosslinking degree before heat vulcanization foaming is started, the vulcanization speed and the foaming speed can be matched, and the problems that foam holes are not uniform, the foaming rate is low and the heat conductivity coefficient is low are solved. The obtained rubber foam material has excellent properties of uniform foam holes, the high foaming rate, the high heat conductivity coefficient, the high compression rate, the high rebound resilience, the low weight, good insulation, damping, sound absorption and the like, the technology is simple, operation is convenient, the prevulcanization time is shortened, and the rubber foam material can be widely applied to a heat conducting gap interface material of an electronic product.