Si3N4 ceramic surface was metallized using multi-ionic composite coating technology. The obtained Cu-Ni-Ti composite coating was examined and evaluated by energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffusion (XRD) and sound emissive scratch test (SEST). The composite coating composition, the element distribution, the phase structure of the deposited coating, and the jointing mechanism of steel/ceramics were analyzed. It was found that the obtained alloy coating layer contained elements such as Cu, Ti, Ni and Fe, etc, and no element segregation was observed. XRD result showed that the diffusion coating alloy layer was composed of Cu2Ti4O, Cu, NiTi and CuTi2. Sound emissive scratch test (SEST) results revealed a good adhesion between the diffusion coating alloy layer and ceramic, and no spallation occurred under the maximum load of 100N.