In World War I, the air force was only an auxiliary force on the battlefield and could not decide the outcome of the war. By World War II, all countries had developed more practical bombers and fighters, and winning the air superiority was an important factor to win the battlefield victory. Because of the importance of air superiority, the status of the air force has been greatly improved and it has become an independent arm as important as the army. With the improvement of the status of the air force, the demand for pilots in various countries is increasing. Because it is a new arms, when World War II just broke out, the number of pilots in various countries was small, and most of them were old pilots with long-term flying experience. With the continuous expansion of the war, pilots on the battlefield are constantly killed and captured, and the demand for reserve pilots in various countries is also expanding. In order to make up for the shortage of pilots, countries have begun to make plans to train new pilots. After the war broke out, Germany attached great importance to the technical training of new pilots. There is a special flight school in Germany, which has developed four subjects to examine the skills of pilots. Only after all of them are qualified can they become air force pilots. There are many ace pilots trained by German flying schools, the most famous of which is Major Hartman. After 1942 obtained fighter pilot qualification, Hartman shot down 352 fighters in the next three years. Because the combat mode of modern fighters has changed, Hartman's record is hard to be broken in the future.

German pilots have always been striving for perfection and their quality has never declined. Compared with Germany, Japan's industrial conditions and resource conditions are backward, and it does not have enough ability to cultivate reserve forces. Only in the early stage of World War II, a group of highly skilled pilots were trained. By the end of World War II, the newly recruited pilots in Japan only received temporary training in simple flying skills and were sent to the battlefield. Because Japan advocated suicide attacks, many excellent pilots were incorporated into Kamikaze Flying Team, resulting in few old pilots left in Japan at the end of World War II.

The United States was the best country to train pilots during World War II. American pilots have strong comprehensive ability and strong reserve force. As the country with the strongest industrial capacity in the world at that time, the United States never lacked planes to train new recruits because it entered the war late. Before the Pearl Harbor incident broke out, the United States had trained hundreds of thousands of reserve pilots in case of emergency. When it comes to war, the more planes, ships and pilots the United States participates in the war. American pilots have long training time and excellent training conditions. Because American flight training schools provide free training and can not join the army after training, the number of students far exceeds that of other countries.