The utility model relates to a high-temperature heat treatment tubular furnace with controllable thermal expansion deformation of a metal furnace tube, which mainly solves the technical problem of thermal expansion deformation of the existing high-temperature long furnace. The technical scheme of the utility model is as follows: the nursing bed comprises a bed body, the utility model discloses a high-temperature heat treatment tubular furnace with controllable thermal expansion deformation of a metal furnace tube. Tube furnace mounted on base, the whole long furnace tube is divided into a plurality of sections of short furnace tubes; wherein the short furnace tubes are connected through flanges by using negative thermal expansion furnace tubes or high-temperature corrugated tubes, the airinlet tube is arranged above the tube furnace and is respectively connected with the short furnace tubes through pipelines, the air outlet tube is arranged below the tube furnace and is respectively connected with the short furnace tubes through pipelines, and each short furnace tube is provided with a temperature thermocouple and extends into the short furnace tube.