The work aims to study the effect of ultrasonic amplitude on the flow characteristics of laser cladding WC ceramic particles during the solidification process in the molten pool, so as to prepare WC/IN718 cermet coating with high hardness and good high temperature wear resistance on the surface of IN718 nickel base superalloy. The distribution of WC ceramic particles in the cross section of composite coating under different ultrasonic amplitudes was observed by VHX-1000 superfield microscope. The microstructure and phase composition of the composite coating were characterized by OM, SEM and XRD. The microhardness and high temperature wear resistance of the composite coating under different ultrasonic amplitudes were studied by microhardness tester and rotary high temperature friction and wear tester. When the ultrasonic amplitude was 22 μm, the average microhardness of the composite coating was the highest (562HV0.2), 49.9% higher than that of coating without ultrasonic application, and the high temperature friction coefficient (0.4) of the composite coating was 67.0% lower than that of coating without ultrasonic application (0.6). The wear mechanism of the composite coating was oxidation wear and slight abrasive wear. Due to the influence of ultrasonic field on the acoustic flow strengthening and cavitation effect in the laser cladding process, WC ceramic particles gradually float up in the molten pool, eliminating the deposition effect of WC particles at the bottom of the molten pool. In addition, due to the thermal effect of the ultrasonic field, as the dissolution rate of WC particles in the molten pool increases, the dilution rate of the composite coating also increases accordingly. The average microhardness and high temperature wear resistance of the composite coating applied with the ultrasonic field are significantly improved.