Basically, after graduating from graduate school, you can try to send resumes everywhere. Of course, you need to find a specific company, mainly a company that can help you get to work (H 1). Basically, when companies want to recruit people, they will indicate whether they can apply for a work visa, because not every company will invite people who need to apply for identity. If the company does not indicate it, be sure to indicate it on your resume.
It doesn't matter if you don't find a suitable company. You can go on to graduate school. After graduation, you can legally stay in the United States to find a job (OPT) for a whole year. In the meantime, you can send your resume desperately. If you are in an eastern city, try some places with more companies in China. Basically, they all prefer to hire people from China. A friend of mine couldn't find a job after graduating from graduate school in Chicago for half a year, but he came to the west (Los Angeles) and successfully found a company that could help apply for a work visa within two months. Now I have got the H 1 visa for 2 years.
If you want to get a permanent residence permit (green card) through a work visa, you won't get a green card automatically after six years, as the one upstairs said, because the immigration law in the United States is very complicated now. As far as I know, if you want to get a green card through a work visa, you need the company to help you. You can consult local immigration lawyers, who should be more professional, but I can tell you a similar direction. ....
Good luck with your study in America!