Abstract: The picosecond laser pulse neutron source experiment was demonstrated on Xingguang-Ⅲ facility. A good neutron signal was measured by liquid scintillator detector. The neutron energy distribution with time was obtained by time-of-flight method, and the charge between different energy intervals was acquired by the ratio of the integral of oscilloscope voltage and time to oscillator input resistance. Geant4 calculation model for liquid scintillator detector under experimental and calibration cases were established, and the neutron sensitivity was obtained by the ratio of the collected optical photons. Neutron energy spectrum for picosecond laser pulse neutron source was calculated, and the neutron yield below 1 MeV in the direction of liquid scintillator detector was 1.04108 sr-1.