Addressing delegates at the ADCS conference in Manchester, Isabelle Trowler said clause 15 of the bill - which has been dubbed the "exemption clause" - could allow children's services departments to break free from "checks and balances that have grown up over the years" for which there is "little evidence of positive effect but a lot of evidence of money and time poorly spent".
Concerns have been raised that the legislation poses a "huge threat" to the rights of vulnerable children and young people. It has also been suggested that it could pave the way for private companies to get involved with child protection provision.
But Trowler said she is confident that the legislation is intended to help children's services departments improve the quality of practice.
"Contrary to the media headlines, this is not some kind of sinister political plot to overthrow public authorities or a ruse to wipe out decades of children's rights," Trowler said.
"We need to think a little deeper about what is really being offered here.
Trowler said that from her access to discussions between civil servants and ministers, she is reassured that the bill is "entirely honourable", but added that there should be debate so concerns can be explored.
"Those of you who feel a little lukewarm about this part of the bill might want to warm up a bit, otherwise we may thwart unintentionally, great plans and ideas that your colleagues have about the need to free up this complex and resource-stretched system," she said.
"They will be our testing ground and we shouldn't stand in their way."
The Children and Social Work bill is currently going through committee stage in the House of Lords.