Polyurethane foam has been widely used as building materials for energy savings. But, it is weakness to fire because of its flammability. Polyurethane foam as solid fuel occurs combustion and fire through pyrolysis process. Therefore, understanding the pyrolysis process is essential for fire safety. In this study, the pyrolysis behavior of polyurethane foam was investigated using thermogravimetric analysis (TGA). The results showed that pyrolysis occurred through two distinct mass reductions. The key parameters of pyrolysis reaction rate, such activation energy and pre-exponential factor, were determined based on various model-free and model-fitting methods. Additionally, numerical simulation was conducted using fire dynamics simulator (FDS) to examine the suitability of the pyrolysis modeling from a fire perspective. As a result, it was confirmed that FDS pyrolysis model numerically predicts the two-step reaction of polyurethane foam.