The two victims, both 15, are being treated in hospital. One remains in a critical condition.
The attack happened at Kingsdale Foundation School at about 15:30 GMT on Thursday.
The teenager accused of attacking the pair has also been charged with grievous bodily harm and possession of an offensive weapon.
He will appear at Camberwell Magistrates' Court on Saturday.
A 15-year-old boy has been charged with attempted murder after two pupils were stabbed at a school in Dulwich.