可以。48小時之內離開UK都可以。詳情看:https://www.gov.uk/check-uk-visa/y/china/tr
https://www.gov.uk/check-uk-visa/y/china/transit/somewhere_else/yes
As long as
"you have a valid USA permanent residence card issued by the USA on or after 21 April 1998"
don't even need a transit visa.