You Do Need power plug adapter while traveling from Taiwan to Thailand.

Here is Why You Need An Adapter

The outlet and plug type used in Thailand are A, B, C and O and in Taiwan are A and B. This is how they look like.

Taiwan

In Taiwan, outlets of type A and B are in use.

Type A

Type B

Thailand

In Thailand, outlets of type A, B, C and O are in use.

Type A

Type B

Type C

Type O