The invention discloses an in-situ combustion layered electric ignition gas injection well wellbore temperature distribution determining method and a device. The method comprises the following steps: (1) dividing a section of wellbore from the top of an ignition gun to the bottom of an inner pipe into multiple wellbore units dl in the axial direction, and letting l=0 and k=1; (2) calculating the temperature of air in the inner 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 outer pipe wall of a heat insulation pipe, the thermal resistance of a heat insulation layer, the thermal resistance of the inner pipe wall of the heat insulation pipe, the thermal resistance of the wall of a screen pipe, the thermal resistance of the wall of an oil pipe, the thermal resistance of air in the annulus between the inner pipe and an outer pipe, the thermal resistance of the wall of the inner pipe, and the thermal resistance of air in the inner pipe; (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 inner pipe; (7) calculating the temperature of air in the annulus between the inner pipe and the outer pipe; and (8) letting l=l+dl and k=k+1, repeating steps (3) to (7) for iterative calculation, ending iteration until l>=L, thus obtaining a temperature curve of the inner pipe and the outer pipe. Calculation is simple, and the precision is high.