you can get a job by applying for them.
the same from any country.

Some advertisement push here ...

https://jobs.echinacities.com

286535 Jobs in China

I ain't sure about the 'easily' part .. 

Short answer; no unless you have a Nobel Prize or are a world class sportsperson.

And you know, the coof is still about. I'm not sure whether Nigeria has been blamed for its origin, spreading or reinfection in China yet. If not, it will join the list.

There are plenty of Nigerians in China in jail for organ smuggling, so I would suggest you become an attorney for the downtrodden migrants from your home country that are rotting away in Chinese jails eating an apple for lunch and noodles for dinner, if they still walk the earth.

It seems that Guangzhou region has a large Nigerian migrant force. Perhaps you can focus on that area of China. I am not sure what they actually do there, or if it is legal. If you are looking for easy, then that is the "easiest" way I see for you. Realistically, unless you have something that China needs or wants, then stay in Nigeria, or look elsewhere. One of your biggest setbacks for coming to China is not so much your country of origin, but the color of your skin (if is is dark in color).