Under 45 years old. According to the official website of Henan Education, the training plan for 10,000 primary and secondary school principals in Henan Province should be under 45 years old, regardless of gender, mainly to lay the foundation for training educators. Henan Province, referred to as "Yu" for short, is the provincial administrative region of People's Republic of China (PRC), with Zhengzhou, the capital, in the middle of China.