We originally design a highly efficient NdYVO4/KGW Raman laser at 579.5 nm. The KGW crystal is specially coated to prevent the Stokes wave from propagating through the gain medium so as to minimize the cavity losses. Moreover, we explore a new output coupler with double-sided dichroic coating to exterminate the leakage power of the Stokes wave to lead to a remarkable improvement for the output efficiency. The maximum output power can be up to 10.5W at a pump power of 40W. The conversion efficiency of the diode pump light to yellow laser output can be increased to 26.3.