ABSTRACT Most noise of underground experiment is from muon-induced neutron process. Underground neutron fluxes are difficult to measure so most study about this are via simulation. It is important to check the normalization of the simulation by a measurement. We use NE213 detector and Helium-3 detectors to measure the neutron spectrum. We also perform GEANT4 simulation for reconstructing the neutron energy. We use different neutron sources for the experiment. First, we hang the source on nylon and place detectors near the source for an energy measurement. We then perform GEANT4 simulation to find the response function of the NE213 detector. In this way, we can unfold the measurement result to get the real energy spectrum.