The Ken Buchanan Foundation has commissioned sculptor Alan Herriot of Powderhall Bronze studios to create the figure, estimated to be finished in March 2020.
Mr Herriot has already completed a maquette, or smaller-scale model of the statue.
He will bring this to a dinner hosted by the Ken Buchanan Foundation on Friday to raise money for a plinth for the statue.
Buchanan still ‘cannot believe’ that there will one day be a statue of him in his home city.
“I’m just a wee boy from Northfield, I can’t believe I’m being honoured in this way,” he said.
“I’ve worked hard, I’ve trained hard to win the titles, and to get where I am.
“But I still just can’t believe it.”
The £50,000 statue will show Buchanan in his prime, complete with the Lonsdale Belt he won in 1973.
When cast it will be slightly larger than life-size.
“I’m really excited to see the statue,” said chairman of the Ken Buchanan Foundation Owen Smith.
“It looks great at the moment, and Alan is about to start putting the clay on. It’s going to be amazing when it’s finished.”
The Ken Buchanan Foundation was set up by Owen Smith, Peter and John Swanston, and Alasdair Clive in April 2016 to campaign and fundraise for a permanent memorial to Ken Buchanan.
It aims to continue running after the statue is unveiled, as a legacy of Buchanan’s sporting achievements.
The location of the statue is still to be decided, in consultation with Lord Provost Frank Ross.
Potential locations include the top of Leith Walk at the new St James shopping centre, or at Meadowbank Stadium.
Buchanan was also recognised with the prestigious Edinburgh Award in March 2017.
His handprints have been set in gold in a flagstone outside the council headquarters.