如题。。。多谢高人指点 
UKBA 网站上是这样说的
If you currently have permission to stay in the UK under any of the following immigration categories, you can apply to Tier 2 (General) from inside the UK:
any Tier 1 category
Tier 2 (Sportsperson)
Tier 2 (Minister of religion)
Tier 2 (Intra company transfer: established staff), if you are applying to switch sponsor
Tier 2 (Intra company transfer) under the Immigration Rules n place before 6 April 2010, if you are applying to change sponsor
any Tier 4 category
Tier 5 (Temporary worker - creative and sporting), for a job as a professional footballer - but you must meet the Tier 2 requirements, including English language
dependent partner of a Tier 4 migrant
Highly Skilled Migrant Programme
innovator
Fresh Talent: Working in Scotland Scheme
International Graduates Scheme (or its predecessor, the Science and Engineering Graduate Scheme)
Business and Commercial work permits (except multiple entry work permits)
Sports and Entertainment work permits (except multiple entry work permits)
Jewish agency employee
Member of the operational ground staff of an overseas-owned airline
minister of religion, missionary or member of a religious order
overseas qualified nurse or midwife
person writing up a thesis
postgraduate doctor or dentist
representative of an overseas business
representative of an overseas newspaper, news agency or broadcasting organisation
student
student re-sitting an examination
student nurse
student union sabbatical officer