Abstract: Hydraulic model of lateral orifice jet is set up.Velocity distribution of the vertical axial surface of lateral orifice jet is measured with PIV system in different discharges under non-threshold and with-threshold conditions.The velocity distribution laws of lateral orifice jet are summarized and summed up through methods such as dividing flow field structure and extracting flow field cross section.Based on the experimental results,the on-way curves of maximum velocity of the cross-section and the relative...