In this paper, we demonstrate the performance parameters and stability of the FEL-III beamline of Shanghai high repetition rate X-ray free electron laser and extreme light facility (SHINE). FEL-III beamline covers the photon energy of 10--25 keV, which is the FEL beamline with the highest energy among the initial three beamlines in SHINE. In the studies and analysis of performance parameters and stability of sources, the electron beam shot noise, the transverse position and incident angle jitter of the electron beam launch condition, and the horizontal position misplacement of the quadrupoles are taken into account. The results provide a solid and clear illustration for the possible performance and stability of the light source. It will also serve as a reference for the design of the optical beamlines and the experimental endstations, and it will provide reference for potential user experiments.