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

Here is Why You Need An Adapter

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

Eritrea

In Eritrea, outlets of type C and L are in use.

Type C

Type L

China

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

Type A

Type C

Type I