In this paper, mathematical model of low temperature radiant floor heating system (LFRS) is established for the process of heat transmission. Through numerical simulation, the temperature field is calculated by finite-element method(FEM). The thermal comfort and the effect of saving energy are analyzed. By the dynamic simulation for the real operation, it is shown that LRFS is in a higher sanitary condition and thermal comfort. Furthermore al kinds of energy sources are made available in this system. The result is of great importance for the design, construction and operation of this sort of system