The toroidal field (TF) coil is a crucial system in the tokamak, which provides the main magnetic field to confine the plasma. One TF coil of the China Fusion Engineering Test Reactor (CFETR) will be constructed with the support of the Chinese government in the next five years. In order to study the quench behavior of the CFETR TF coil, the assumed quench initiation at the maximum and minimum temperature margin position of the TF coil is analyzed, and the effect of the quench detection threshold on the hot spot temperature is studied. It is found that 0.5 V quench detection voltage leads to hot spot temperature above 250 K in the low-field region. In order to meet the design criteria of the hot spot temperature, the quench detection voltage should be less than 0.2 V.