Bulk YbxCo4Sb12 (x=0.27, 0.28, 0.29) alloy samples were prepared by melt-annealing-discharge plasma sintering. XRD, SEM and EDS analysis show that Yb doped single phase CoSb3 thermoelectric material has been successfully synthesized. When the Yb content increases from 0.27 to 0.29, the power factor of the material increases first and then decreases with the increase of temperature, while the thermal conductivity decreases first and then increases. Due to the relatively high power factor of 1815 μWm-1K-2 and the relatively low thermal conductivity of 2.23Wm-1K-1, the alloy Yb0.29Co4Sb12 obtained a higher ZT value of 0.62 at 773K. The Al-Ni protective coating of Yb0.29Co4Sb12 was sputtered by magnetron sputtering method. SEM and EDS showed that the coating bonded well with the substrate, and the thermoelectric properties of Yb0.29Co4Sb12 element protected by coating had good stability. The welding behavior of the joint between Yb0.29Co4Sb12 and electrode Mo50Cu50 was studied by Ag40Cu60 solder. It was found that the interface was well bonded, and no serious diffusion of Co, Sb, Yb, Mo and other elements occurred at the interface.