Abstract: The H-8 horizontal channel of CARR is an experimental channel to provide neutrons, which can provide a stable radiation field. For different neutron experiments, the required neutron energy spectrum shapes are often different, so accurate measurement of neutron energy spectrum is of great significance. A passive single sphere neutron spectrometer with gold foils as thermal neutron detector is developed to measure the neutron energy spectrum of H-8 horizontal channel. The neutron energy response in 10^-11-15 MeV is calculated by MCNP and the rationality of the energy response is analyzed. The single sphere spectrometer was tested in the conduit hall of CARR, the activity of each gold foil was measured by high-purity germanium detector, and the experimental data were calculated by UGA (unfolding based on genetic algorithm). The results show that the neutron energy range emitted from the conduit hall is 10^-9-10^-6 MeV and the single sphere neutron spectrometer can give accurate neutron energy spectrum data, and can be applied to the measurement and research of neutron energy spectrum in H-8 horizontal channel of CARR.