I work as a maintenance man in a communication maintenance company. I want to improve my education. What major should I study?

Learn communication engineering! It is good for you to improve your knowledge of network and communication equipment and improve your maintenance skills. Computers are basically irrelevant to your current job. The mobile communication principle of communication major is your key point. In addition, see if there are any direct upgrades, like in Jilin University. It seems easy to ask yourself.