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

Here is Why You Need An Adapter

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

Pakistan

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

Type C

Type D

China

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

Type A

Type C

Type I