Due to the 4J29 Kovar alloy’s similar character of difficulty to be cut with austenitic stainless steel, the quality of holes obtained by traditional drilling is poor. In order to study the factors affecting the quality of 4J29 Kovar alloy drilling and improve the quality of drilling, traditional drilling and ultrasonic vibration-assisted drilling experiments of 4J29 alloy under different processing parameters were carried out, and the drilling axial force, hole diameter error and hole wall roughness were measured. It is found that under different processing parameters (cutting speed v=0.314–0.942m/ s, feed speed f=10–30mm/min), ultrasonic vibration-assisted drilling can reduce the drilling axial force by about 18.45%, with an average decrease of 35.37N. Ultrasonic vibration-assisted drilling can improve drilling accuracy, and the average hole diameter error is reduced about 17.9μm, with a decrease by 31.5%. Ultrasonic vibration-assisted drilling can improve surface quality. For the arithmetic mean deviation R_a of contour, ultrasonic vibration-assisted drilling reduces the average surface quality by about 28.4%, which is 0.4862μm, and the average maximum contour height R_z is decreased by 20.0% (about 2.4940μm). The experiments have shown that ultrasonic vibration-assisted drilling of 4J29 Kovar alloy has more advantages than traditional drilling, and can contribute to higher quality drilling holes.