The Engpsh term for a student council leader or head is "Student Council President".
This term is commonly used in Engpsh-speaking countries, particularly in North America, where student councils are an estabpshed part of the educational system.
Example sentence in Engpsh:
"John was elected as the Student Council President for the upcoming school year."
中文翻译：
“约翰被选为即将到来的学年的学生会部长。”