The temperature distribution in a bench‐scale fixed bed Fischer–Tropsch reactor using Co‐based catalyst was investigated under conditions of 2 MPa and 458 K at various syngas partial pressures and space velocities. The single‐tube reactor had a diameter of 0.05 m, which is representative of the diameters used in industrial applications. With a special designed temperature measurement, the detailed temperature distribution in a bench‐scale reactor was reported for the first time. The changes of maximum temperature in the bed and hot spot region were discussed at different N2 flow rate and gas hourly space velocity. A 2D pseudo‐homogeneous fixed bed reactor model was developed using ANSYS Fluent. A position‐dependent heat‐transfer coefficient, which considered more accurate in temperature prediction, was applied. The model was validated against both the reaction results and the measured temperatures. The inferred properties within the reactor were analyzed to give insight as to how to increase the reactor production capacity.