The invention discloses a boron-coated neutron detector. The boron-coated neutron detector comprises: a cathode tube, wire electrodes, and insulated end plates. Inside the cathode tube, a plurality of channels is formed along a longitudinal direction, and a wall of each channel is coated with a boron material. The wire electrodes working as anodes are longitudinally disposed in each channel, and the wire electrodes are suitable to be applied high voltage. The insulated end plates are fixed on each end of the cathode tube, and the wire electrodes are fixed with the cathode tube through the insulated end plates. Preferably, the cathode tube is formed by splicing a plurality of substrates coated with the boron material. Through disposing the plurality of channels which inner walls are coated with the boron material in the cathode tube, the neutron detector not only increases detection efficiency, making the detection efficiency reach or even higher than that of a same size 3He neutron detector, but also has a much cheaper price than that of the3He neutron detector.