The invention provides an ultrasonic contrast agent applicable to HIFU (high intensity focused ultrasound) as well as a preparation method and application of the ultrasonic contrast agent. The ultrasonic contrast agent consists of 30-70 parts of a solution containing fluorocarbon drops by volume, 40-70 parts of egg white by volume and 10-40 parts of a thinner by volume, wherein the fluorocarbon drop consists of lipidosome and liquid fluorocarbon covered in the lipidosome. With the existence of the egg white, the ultrasonic contrast agent disclosed by the invention can coagulate at transient high temperature so as to take an effect of sealing bubbles, therefore a stable echo enhancing signal is generated in a focused target area to accurately monitor tissue injury region range in the focused area in real time; in addition, by virtue of the fluorocarbon drops, the ultrasonic contrast agent can release a great amount of bubbles in response to controllable local temperature so as to greatly enhancing a cavitation effect of focused ultrasound; and moreover, on the basis of the property of the egg white which coagulates at high temperature, the composition disclosed by the invention can also block blood vessels, so as to achieve effects such as inhibiting the reoccurrence of tumors.