The NSW government announced the museum's refurbishment on Monday as part of next week's state budget and revealed the Tutankhamun: Treasures of the Golden Pharaoh exhibition will run for six months from early 2021.
The display will mark a centenary since British archaeologist Howard Carter discovered the boy king's sealed tomb in 1922. It's believed Tutankhamun died around 1324 BC, aged 19.
Sydney is one of 10 cities worldwide to host the collection - the largest Tutankhamun exhibition to leave Egypt.
The bones of the project were revealed by Arts Minister Don Harwin and Treasurer Dominic Perrottet, including the expansion of exhibition halls, an extension of the museum's striking Crystal Hall glass entrance and new education spaces to double student visitors to 100,000 a year.
Macquarie University Professor of Egyptology, Naguib Kanawati, says it is "unbelievable" more than 150 artefacts from the pharaoh's tomb, including 60 ancient items never before shown outside Egypt, will travel the distance to Sydney.
"To my knowledge, the Egyptian government has decided not to let Tutankhamun out of the country," he told AAP at the announcement.
"A few years ago, another exhibition of this kind went to the United States and something was broken."
While it is not made of gold, Tutankhamun's "wishing cup" or chalice - carved from transparent alabaster stone in the form of a blooming lotus - is an "exquisite" example of skill within the royal workshop, Prof Kanawati said.
"We are not judging the monument because of its gold value ... it's the ability of the ancient sculptor to do it, to handle such complicated sculpture from a piece of very hard stone is fantastic," he said, noting the Egyptian artist was never named.
But for those fascinated by the mummification process, the collection also includes a miniature, canopic gold coffin, inlaid with precious stones, which once held the king's dehydrated liver wrapped in linen bandages.
Three others, made as exact miniatures of the larger mummy coffin, housed the intestines, stomach and lungs.