The invention discloses a hydrodynamic performance measuring mechanism in a stability testing device for a ship model in
waves. The hydrodynamic performance measuring mechanism comprises a base supported by a trailer measuring bridge in a sliding mode, a supporting frame penetrates through the base and is fixedly connected with the base, a
pulley at the upper end of the supporting frame is provided with a steel
wire rope in a winding mode, one end of the steel
wire rope is connected with a balance weight, and the other end of the steel
wire rope is connected with a heaving rod. The heaving rod penetrates through the base and can slide up and down, the heavy rod is fixedly connected with a middle bracing wire extending end in a bracing wire type sensor, the bottom end of the heavy rod is sequentially provided with a three-component
force sensor and a supporting seat, the two side walls of the supporting seat are provided with pitching shaft, and the pitching shaft and a rolling shaft form a cross-shaped shaft. The rolling shaft is arranged on fixed seats on the two sides of the supporting seat in an erected mode, and the pitching shaft and the rolling shaft are connected with rotational potentiometers. The other end of the rolling shaft is sequentially connected with a rolling
torque sensor and a rolling locking device. According to the hydrodynamic performance measuring mechanism, the longitudinal force, the
transverse force, the yawing torque, the pitching displacement and the heaving displacement of the ship model can be measured, and the yawning torque or the rolling displacement can be measured through locking or unlocking of rolling movement.