In a room with a large glass area, the influence of solar radiation on the floor radiant air-conditioning system in summer cannot be ignored. Firstly, the projection equations method is used to solve the distribution of solar radiation in the room, and then a frequency-domain RC coupled dynamic heat transfer model of the room with floor radiation is established considering solar radiation. This model can perform dynamic heat transfer calculations for radiant floor rooms considering solar radiation, and solve the required node heat flow and temperature, and the calculation of variable working conditions is convenient. Using MATLAB software to write the calculation program of the model, and taking a certain working condition of a south-facing room in Chongqing as an example on July 21, the calculation found that: solar radiation significantly increases the floor surface temperature and indoor air temperature, which is conducive to improving floor cooling When only considering the external envelope structure load, the floor solar radiation heat gain accounts for an average of 16.75% of the total floor cooling capacity, with a maximum of 58%, and the solar radiation distributed on the inner and outer walls will increase its The radiation heat exchange with the floor, so the solar radiation cannot be ignored.