Your composition is good but your handwriting still requires improved.

Your composition is good but your handwriting is still required to be improved.

祝你进步！

Your composition is good but your handwriting still requires improving.
Your composition is good but your handwriting still requires to be
improved.

Need.request.require doing表示需要被怎样怎样,把improved改成improving就可以。正确的形式还有加上to be done,意思一样。