Arriving PEK at 12:20pm by Cathay Pacific.heading to Urumqi at 14:35 by China Southern.

It's international to domestic transfer from T3 to T2. Generally speaking, you need to have at least 160 minutes to make this connection. Thus your time is not enough. You are advised to change the schedule of the next flight as soon as possbile.
By the way, the correct transfer procedures are the following:
Inspection & Quarantine, Exit and Entry Frontier Inspection - Baggage Claim - Customs Inspection - Going through Transfer Formalities - Security check - Waiting & Boarding