This document explains hydrodynamic force of water jet propulsion and kinematic characteristics of double water jets ship. Firstly, study on the water jet thrust based on the theorem of momentum. Then discuss the hydrodynamic performance of the water jet reversing bucket, calculate the backing force produced in the condition of different flow rate and nozzle angle. On the basis of hydrodynamic analysis of water jet, we next explore the various motion modes of double water jet propulsion ship, especially kinematic analysis of ship’s in-situ rotary movement and transverse movement.