If you're writing in English as a second language and you're serious about publishing your academic paper, then you must write it in English from the beginning. Academic writing is often very technical, so journals require precise meaning in any papers that they publish. It's the content of your paper that makes the journal want to publish it, but language issues can be the cause of rejection.
Why you shouldn't write your paper in your first language, and then translate it into English
It's important to understand that languages work in different ways. Take the phrase "I love you". If we translate that into Spanish, then we get "Te Quiero", but if we translate that directly back into English we get "I want you" – which in turn, means an entirely different thing!
Your academic paper must be written in English from the beginning to avoid any limitations in a translator's ability to interpret your exact meaning. Human translators are the best, as they can think critically as they translate, but they are still limited by their language abilities. Machine translation is cheaper, but it is only as good as its programming, and it can't think critically – although that may change with AI advances.
Get your supervisor or colleagues to check the content of your first draft.
Content is critical, so, with that in mind, consider language improvements as the last step in your journey to publish your academic paper. Write your paper in English from the beginning and try to correct your language as much as possible as you work towards the completion of your first draft. Once you're happy with the content of your first draft (discounting the imperfect language), then ask your supervisor or research colleagues to check it to see if it could be published in your target journal. They should have experience of publishing in journals and will be able to offer critical advice on how to improve your paper.
Find the style of your target academic journal
Most publishers issue a style guide, which is a set of standards that should be used so that your article fits in with the writing style of the rest of the publication. First see if the journal that you wish to publish your paper in has a style guide, if so, read it carefully and begin to alter your writing to fit within the style rules of the journal. If there isn't a style guide available, take some time to read through other papers that have already been published in the journal and look for formatting, phrasing, nuances, idioms, etc.
Remember, if there is a downloadable style guide, then you can download it and submit it to your academic editor with your finished paper when you're ready.
Get an academic editor to work on your paper before submitting it
Once you're happy with the content of your paper, then you're ready to prepare it for publishing. It's advisable to submit your paper to an editor who regularly works with writing in an academic style, as that will produce the best results. Be wary of editors that aren't academic specialists, as you may get an editor who has expertise in another style of writing. Sadly, we do get papers that have been edited by other companies that have been rejected due to language issues from time to time.