International Economic Law or International Business Law?

This depends on personal preference, the difference between the two is not very big, are quite good.

International economic law:

International economic law refers to the adjustment of the legal norms between states; between international organizations; between states and international organizations; between states and other private countries; between international organizations and private individuals, as well as between private individuals of different nationalities, the mutual economic relations of the general name.

International commercial law:

International commercial law was created and developed with the emergence of international commercial relations. From the date of its creation, it is an independent legal sector. In recent times, the manifestation of international commercial legal norms has seen a diversified and complex development trend. At present, we should break through the limitations of the traditional division of legal departments, establish the status of international commercial law as an independent legal department, clarify its system structure, and comprehensively analyze a variety of legal sources as a whole, in order to promote the unity of international commercial legal norms, and better adapt to the needs of the development of international commercial exchanges.