To participate in the DV Lottery, you must have completed the equivalent of a US high school education. This is defined as a 12-year course of primary and secondary education. Completion of most international secondary education programs will qualify you.
This is only the minimum requirement and, of course, if you have achieved a higher level of education, this is viewed favorably by the US Citizenship and Immigration Services (USCIS).
You can still participate if you do not satisfy the minimum education requirement if you have completed vocational school or have worked at least 2 years (within the last 5 years) in a qualified job that requires at least 2 years of training or experience to perform. The list of qualified occupations is available for you to consult.