In order to study the hydrodynamic characteristics of shallow submerged jet with depression angle, detailed flowing field of plunge pool was obtained by the Particle Image Velocimetry(PIV)technology, and the law of the two-dimensional longitudinal velocity distribution was analyzed systematically. Formulas of the velocity attenuation along the flow-path and the velocity distribution of cross section perpendicular to the primary flow in the submerged plunged jet region and wall attached jet region have been obtained from the study. The results showed that the shallow submerged jet issued into the plunge pool by a incidence angle and the depression angle of dived jet was larger than the incidence angle. Attenuation ratio of velocity in the submerged plunged jet region was greater than that in the wall attached jet region. Besides, the velocity distribution of the cross section perpendicular to the primary flow had similarity or self-holding.