How to correct my pronunciation?

You could practice reading some English novels, poems, or liseteng some English radios. Watch more and more English movies and you will have a sense of your pronunciation...

Firstly, decide which one you like better, British English or American English.
Secondly,listen to BBC or VOA and then imitate their pronunciation.You would better imitate sentence by sentence, and recite some paragraphs even the whole article.Pay attention to the important words.
Thirdly, try to spaek in the way you have learneed when you speak English in daily life.
Last but not least, persist and do not give up.