It will feature in Sunday's first episode of the new series of the long-running programme, which was recorded at Tewkesbury Abbey in Gloucestershire.
Expert Fergus Gambon said it was "unique" and "one of the most important English baby houses in existence".
The doll's house was built in 1705 and is extremely well preserved.
In a first for the programme, a camera crew went to film at the home of the object's owner, after just a few dolls were taken to the recording, which took place in May.
Mr Gambon, who is the son of actor Sir Michael Gambon, said: "As soon as I saw the dolls I recognised the importance of it.
"And it is quite a large object, it's extraordinarily fragile, it's not something that you can just shove in the back of the car and bring over.
"So if we wanted to show the viewers what the house was like, this was really our only chance."
The doll's house is well preserved, with the dolls in their original clothes, and was made on the Isle of Dogs for a Miss E Westbrook.
It has been in the owner's family ever since, being passed down the female line for generations.
Mr Gambon said he had known of the existence of the doll's house after having seen photographs of it in a book from the 1950s.
"I saw the dolls first and I recognised them immediately from the pictures," he said.
"The extraordinary thing about the Westbrook is the fact that it's remained in the family since it was made, and it is essentially a little time capsule."
The Antiques Roadshow at Tewkesbury Abbey will be shown on Sunday August 28 at 20:00 BST on BBC One.
An early 18th Century doll's house, described as "of national importance", has been valued by the BBC's Antiques Roadshow at more than £150,000.