This is from the China-Africa Project:

In purely economic terms, China matters a LOT to Africa but Africa is effectively meaningless to China. Last year, China did more than $4.14 trillion in total global trade. So that means Africa represents just 4.8% of China’s global trade balance, effectively a rounding error for the world’s second-largest economy.

For some additional context, consider that China does more trade with just Germany ($225.7 billion)  and about the same with Australia ($194.6 billion) than it does with all of Africa.

More on this here.