[en] The sensitivity for a scintillating-fiber-array neutron detector is studied. The energy response of the detector to neutrons and gamma rays is simulated using Monte-Carlo method. The calibration work is carried out at several specific energies as well. The results show that the tendency of the theoretical energy response curve is in good agreement with that from the experiment. By fitting the experiment data, the energy response of the detector in a wide energy range could be obtained. The detector's neutron-to-gamma sensitivity ratio is about 5.3 for the 2.5 MeV neutrons and 1.25 MeV gamma rays