您的英语作文中存在明显的汉语思维,另外还存在一些语法错误,现帮助您改正如下：
MY TEACHER
When I was a child,I was a bad boy who have always disobeyed the school rules in my school.I threatened most of my schoolmates with beating them on condition that they failed to act in my way.
After moving to a new school,I met the most important person in my life---Miss Chen,who succeed in teaching me how to be a good student and wining my complete respects.
When she met us in classroom at the first time,she told all of us:"From now on,I would like to be your guide to help solve any problems occured in both your life and your studying".at the same time,she had also promised us that she would help improve our performance in terms of morality,intelligence,physical work capacity and arts.
Miss Chen never brought any negative criticism to me,instead,She had always encouraged me to behave better and appointed me as the capital of our class,which successfully made me get around to thinking about what I should do and what I shouldn't do.
Eventually,I become a boy who keep studying hard all day.on account of Miss Chen's pure-hearted help,at last,I obtained the ideal scores in my class.
Thank you!Miss Chen!