In order to improve the microstructure, properties and overall quality of traditional laser cladding coating, the coating was prepared by no-load ultrasonic vibration auxiliary equipment. 304L+La2O3 coating was prepared on 45 steel. The microstructure, phase composition, microhardness and friction and wear properties of the coating were analyzed. The results show that the cavitation effect of ultrasonic vibration and acoustic flow can make the grain of coating finer and improve the microstructure and properties. The average hardness of the cladding layer is 758.2 HV, which is 7.4% higher than that of the non ultrasonic process. The friction coefficient and wear loss are reduced by 6.5% and 12.9%, respectively.