You Do Need power plug adapter while traveling from China to Congo.

Here is Why You Need An Adapter

The outlet and plug type used in Congo are C, D and E and in China are A, C and I. This is how they look like.

China

In China, outlets of type A, C and I are in use.

Type A

Type C

Type I

Congo

In Congo, outlets of type C, D and E are in use.

Type C

Type D

Type E