Yes, he must file. His filing status is Single dependent that is he will not get exemption of $3,400, but he will get standard deduction up to $5,350 of earned income. 1099-MISC income is earned income.
1099 income is Self employed income. He will file schedule C. On the net income (after deducting expenses), he will pay SE tax at 15.3% for that he will file schedule SE.
Read:
Tax News: Independent Contractor or Self Employed Person getting 1099 (instead of W2)