The invention discloses an in-situ combustion general gas injection electric ignition wellbore temperature distribution determining method and a device. The method comprises the following steps: dividing a wellbore into multiple wellbore units dl in the axial direction, and letting l=0 and k=1; (2) calculating the temperature of air in an oil pipe after heating through an electric igniter; (3) calculating the thermal resistance of a formation, the thermal resistance of a cement ring, the thermal resistance of the wall of a casing, the thermal resistance between the air in an oil sleeve annulus and the casing, the thermal resistance of the wall of the oil pipe and the thermal resistance of air in the oil pipe, wherein the wellbore sequentially includes the oil pipe, the casing and the cement ring from inside to outside, the oil sleeve annulus is internally connected with a packer in a position corresponding to the top of an ignition gun, and the oil pipe is divided into an upper section and a lower section; (4) calculating the total radial thermal resistance of the wellbore; (5) calculating the radial heat loss of the wellbore; (6) calculating the temperature of air in the oil pipe; and (7) letting l=l+dl and k=k+1, repeating the steps (3) to (6) for iterative calculation, ending iteration until l>=L, thus obtaining a temperature curve of the oil pipe. Calculation is simple, the precision is high, and the number of iterations is small.