Transport from Taoyuan Airport Terminal 1 directly to Taichung?

There are direct buses between the airport to Taichung. You can find bus no. 1623, 5503 or 1860, any of which will take you to your destination within around 2h and 10min.

Thank you very much for your quick reply.

Beside buses, is there any bullet train direct to Taichung?
Where should we go from the airport to the bullet train station?

Thank you.

Or is there any van which can transport 9~~10paxs from airport to Taichung? Thank you.

Yes, bullet train is available. You can take the airport shuttle bus to Taoyuan High-speed Train Station, where there are direct bullet trains to Taichung.

Do u you mean that you wanna take a van only holding all of you? Well, I remember there are vans for rental. Upon arrival, you can go for consultation.