The invention discloses a tubular LPCVD (Low Pressure Chemical Vapor Deposition) vacuum reaction chamber. The tubular LPCVD vacuum reaction chamber comprises a furnace door, a front flange, a front support flange, a front sealing assembly, a heating furnace body, a back support flange, a back sealing assembly, an end flange, an inner quartz tube and an outer quartz tube, wherein the heating furnace body sleeves the outer quartz tube, the front support flange and the back support flange are respectively located on the outer tube wall of both ends of the outer quartz tube, the front support flange, the heating furnace body and the back support flange are fixedly arranged, the furnace door is connected with the front flange, the front flange covers the front end openings of the inner and outer quartz tubes, the front flange is connected with the outer quartz tube by virtue of the front sealing assembly, the front sealing assembly is fixed to the front support flange, the end flange is arranged on the back ends of the inner and outer quartz tubes, the end flange is connected with the outer and inner quartz tubes by virtue of the back sealing assembly, and the back sealing assembly is fixed to the back support flange. The tubular LPCVD vacuum reaction chamber has the advantages of simplicity and rapidity in disassembly and maintenance and obvious economic benefits, and the maintenance time is shortened.