Abstract: Study on the optimization of solid spallation target in accelerator-driven reactor system are carried out. The geometry of the solid target is optimized. The leaked neutron yield of this optimized target, the leaked neutron spectrum and energy deposition in target are studied. A target assembly consisting of tungsten diskes and water layers is proposed in the present work. The problem of large energy deposition in soild target is solved without decreasing the leakage neutron production.