The invention discloses a hypersonic wind tunnel thermal jet flow interference test gas heater comprising a junction box, electric heating tubes, a tube sheet and a heater casing, wherein the electricheating tubes arranged in an array are fixed on the lower surface of the tube sheet and are inserted downward into the closed heater casing; the junction box is installed on the upper surface of thetube sheet, the wires of the electric heating tubes arranged in the array are bundled in the junction box and are respectively connected to the anode and cathode terminals fixed outside the junction box after being bundled, and the anode and cathode terminals are connected to an external power source to power the electric heating tubes; a control box interface is also installed on the junction boxand is connected to an external computer, and the computer controls the heating power of the electric heating tubes; the upper part of the heater casing has large and small air inlets, and the lowerpart of the heater housing has large and small air outlets; the heater casing and the large and small air outlet pipes have temperature measuring holes respectively. The heater has a simple structure,is sturdy and durable, and has high heat exchange efficiency and stability.