Abstract: The long neutron counter is a kind of neutron detection instrument, which detector efficiency is a constant in some determined range of neutron energy, and is not changed in accordance with neutron energy. The current long neutron counter is designed based on Hanson structure and produced by China Beijing Nuclear Instrument Factory. With Hydrogen-contained proportional counter tube and semiconductor telescope methods, the current long neutron counter has been calibrated with electrostatic accelerator neutron source: 220 keV、500 keV、1.000 MeV、1.403 MeV、3.270 MeV、4.000 and 5.000 MeV single energy neutron beams. The calibration gives results of detector efficiency: 2.881 0×10^-4（1±4.8%） in energy range from 220 keV to 5 000 MeV.