The invention discloses a novel heat treatment process of a drilling rod welding line of a bainite/martensite mixed steel material, comprising the following steps of: step 1, heating a welding line region of a drilling rod to a temperature which is higher than an eutectoid temperature in an intermediate-frequency induction manner for austenitizing; step 2, quenching the drilling rod welding line: conveying the light drilling rod welding line to a quenching coil position and raising the temperature for 30-40 seconds by adopting 320-V voltage; heating the welding line to 880-900 DEG C and preserving the heat for 105-115 seconds; discharging from a furnace and cooling by air, wherein the quenching time is 595-605 seconds; and step 3, carrying out high-temperature annealing of the drilling rod welding line: conveying the quenched drilling rod welding line to the quenching coil position and heating the welding line for 95-105 seconds to 300-400 DEG C in the intermediate-frequency induction manner, and preserving the heat for 355-365 seconds and naturally cooling to a room temperature. With the adoption of the method disclosed by the invention, the yield strength of the obtained welding region is more than or equal to 1000 MPa, the tensile strength is more than or equal to 1150 MPa and the elongation percentage is more than or equal to 13%.