The invention discloses a solid solution heat treatment furnace which comprises a roller hearth type heat treatment furnace and a quenching machine which are connected, wherein the roller hearth type heat treatment furnace comprises a furnace body, furnace walls are arranged at the periphery of the furnace body, a furnace body feed hole and a furnace body discharge hole are respectively and correspondingly arranged in the furnace body, a plurality of furnace roller devices are arranged in parallel between the furnace body feed hole and the furnace body discharge hole, both ends of each furnace roller device are sealed in the furnace walls through a sealing module, each furnace roller device comprises a water cooling support shaft and a roller body, each water cooling support shaft is provided with a cooled water channel, each roller body is provided with an axially perforating cavity, each water cooling support shaft passes through the cavity and penetrates in the roller body, the roller body synchronously rotates with each water cooling support shaft, a containing space is arranged between the outer wall of each water cooling support shaft and the inner wall of each roller body, a plurality of support assemblies are arranged in parallel in the containing space at intervals along the axial direction, one side of each support assembly is connected with the outer wall of each water cooling support shaft, and a predetermined gap is arranged between the other side of each support assembly and the inner wall of each roller body.