The invention discloses a light spot thermal flux density distribution test system. The light spot thermal flux density distribution test system comprises a ceramic installation base, a plurality of temperature sensors, an input and output module, a data processing module, a data display module, a rear end cover plate, a top plate, a bottom plate, a middle supporting plate, two side plates, a speed reducer and a drive motor, wherein one end of the ceramic installation base is fixed to the position of a circular hole in a front end cover plate, the other end of the ceramic installation base is connected with a rotating shaft, the temperature sensors are distributed on the test installation face of the ceramic installation base, the rear end cover plate is provided with the speed reducer, a circular hole used for allowing the rotating shaft to penetrate through is formed in the middle of the middle supporting plate, the other end of the rotating shaft is connected with the speed reducer, the drive motor is arranged on the speed reducer, the drive motor drives the speed reducer to rotate, and rotation is delivered to the rotating shaft so that the ceramic installation base can be driven to rotate. The light spot thermal flux density distribution test system can test whether the thermal flux density distribution of light spots on a whole section is even or not, and the phenomenon that when light spot thermal flux density distribution is not even due to condenser system errors, a hot end part of a thermal absorber is burnt, and even a working medium leaks or explodes is avoided.