Abstract: The invention relates to a method for treating oil sand. The steps consisting of cooling said oil sand to a temperature lower than the glass transition temperature of the bitumen by bringing said oil sand into contact with carbon dioxide in the solid state and applying mechanical energy to the mixture produced. Then melting the solid carbon dioxide in such a way as to produce a multiphase system. The multiphase system is then separated into at least one solid phase and at least one liquid phase. The bituminous phase is then recovered from the separated liquid phase. The invention also relates to a device for treating oil sand, especially designed for implementing said method.