With the use of ultrasonic-assisted diamond cutting, an optical surface finish can be achieved on hardened steel or even brittle materials such as glass and infrared materials. The proposed ultrasonic vibration cutting system includes an ultrasonic generator, horn, transducer, cutting tool and the fixture. This study is focused on the design of the ultrasonic vibration cutting system with a high vibration frequency and an optimized amplitude for hard and brittle materials, particularly for moulded steel. A two-dimensional vibration design is developed by means of the finite element analysis (FEA) model. A prototype of the system is manufactured for the test bench. An elliptical trajectory is created from this vibration system with amplitudes of micrometers in two directions. The optimization strategy is presented for the application development.