No, PEK does not have "airside transit." Airside transit is when you can deplane and stay within the secure zone while moving to your next connection, without passing through Immigration. PEK policy currently requires incoming international passengers to go through Immigration. PEK does have dedicated desks for International Transit passengers to use, after which they can proceed to security and reclear for airside access.

It is true that PEK allows international transit passenger luggage, if tagged through to final destination, to be auto-routed without requiring pickup and recheck by the transit passenger. This is currently not the case at all Chinese airports however.