Chris Woodhead said teachers would be simply unable to cope with the "horror" of further wholesale changes in the forthcoming review by the Qualifications and Curriculum Authority.
He applauded the Government's decision to relax the primary curriculum to allow teachers to concentrate on literacy and numeracy.
Speaking at the Keele conference - where the QCA's chairman had hours earlier articulated the opposite view - he said that there was also a case for giving the best schools more flexibility.
Sir William Stubbs, chairman of the QCA, speaking at the same conference, said the national curriculum had an honourable basis in inclusion and entitlement.
"If we move away from that to think about exclusion, then that would begin to move down a path that I would not be happy to tread too far," he warned.
As well as relaxing the formal academic curriculum, the QCA is being lobbied to prescribe a more detailed personal, social and health education timetable.
But in a breakneck tour of the educational landscape, Mr Woodhead set out his stall firmly against any extra imposition. He said that the Government was right to focus on basic skills and warned ministers against overloading teachers with other initiatives.
"At key stage 4, the Office for Standards in Education will be advising the Government to free things up and allow more flexibility," he said. "I still don't think we've got it right with regard to opportunities to pursue vocational courses for those youngsters who, frankly, haven't made the progress they can in academic learning.
"It doesn't make much sense to prolong the agony of failure that too many have experienced for too long."
Mr Woodhead also defended himself against the claim last week by Professor Maurice Galton of Leicester University that he had contributed to a decline in primary pupils' achievements in English and maths.
Professor Galton, whose study compared nine to 11-year-olds' performance with that of children who were surveyed 20 years ago - blamed the "uncritical imposition of whole-class teaching by Chris Woodhead (which) has encouraged easy riding and daydreaming." He also blames the national curriculum, in an echo of the chief inspector's own views.
Mr Woodhead said he had been misrepresented. "I do think whole-class teaching is important and there has been an excessive reliance on individual work. But I'm not saying it's the only mode of teaching we should use."