Who can tell me,Will i am able to be admitted to UCL or LSE with 570-580 in TOEFL (pbt), but with pretty strong background?

Regarding LSE, I don't think 580 is enough.
When I asked the administrator of LSE, they said the minimum requirement of TOEFL (263) is very strict. But of course it depends on the background of each applicant. So it's worth asking by yourself with your background.