The invention provides a method for removal of RH vacuum chamber bottom channel steel slag. Heat release of an aluminum oxygen reaction process is utilized to perform melting removal on steel slag. The method consists of: preheating: controlling an oxygen lance's position at 5000-5600mm and the gas flow at 400-500m<3>/h, performing baking for 10-20min until steel slag begins to drip at a bottom channel, then raising the ascending gas flow to 120-150m<3>/h; aluminum adding: using an aluminum alloy hopper to add 100-200kg of aluminum wire segment to the vacuum chamber bottom channel position; and slag melting: controlling the oxygen lance's position at 5000-5600mm and the gas flow at 400-600m<3>/h, further performing baking for 5-20min until the aluminum wire segment added into the bottom channel burns and the steel slag melts, and at the end of the aluminum wire segment reaction, adjusting the ascending gas flow to 80-120m<3>/h. The method provided by the invention can realize online removal of bonded steel slag at the bottom of the RH vacuum chamber bottom channel, thereby effectively reducing the RH circulating pipe hang slag, expanding the circulation pipe inner diameter, increasing the RH molten steel circulation velocity, and ensuring the product quality reliable guarantee.