A sodium beacon with bright magnitude can be obtained during backscattering time, by utilizing a long pulse laser with parameters matched with a sending and receiving beacon system. This is helpful to get high SNR in detecting beacon, and to achieve a closed-loop correction at high frequency. Based on a 450 mm telescope and a high-energy long pulse laser, the detection experiment of sodium beacon was carried out, and the backscattering characteristics of sodium beacon were obtained. The intensity data of backscattering light with different launching energy and polarization were collected by CCD and PMT. As high as ～15,000 photons/m2·pulse-1 of backscattering light was detected, and the brightness is close to 4.1 magnitudes during backscattering time. The column density in experiment was derived from analyzing and calculating experimental data. No saturation phenomenon was observed during the whole experimental process. And the feasibility to avoid saturation is verified and a bright sodium beacon is obtained by utilizing a long pulse laser.