West Midlands Mayor Andy Street said the demolition of all the light industrial buildings that will make way for the two-platform facility in Rose Hill is now almost complete.
The next phase will see the underground mine shafts being stabilised before construction can start in the summer.
Bosses said the new station is anticipated to open in the first part of next year, while work on the Darlaston station in Cemetery Road will be finished a short time after.
Walsall Council deputy leader Adrian Andrew said the station is a key part of the authority’s Willenhall Masterplan aimed at encouraging investment and delivering new homes to the area.
Once opened, Willenhall’s station will have two platforms, a footbridge and a 33 space car park as well as improved pedestrian crossing facilities in Bilston Street, linking the town to Wolverhampton and Birmingham New Street.
Mr Street said: “We’re marking very nearly the end of all the demolition of the light industrial buildings that were on the site of the new station. The great thing is you can now see how the station will form.
“The last bit of demolition has to finish and then there will be the final clearance of the site while the next big job will be stabilising all the mine workings underneath the ground here.
“That will mean pumping into the shafts and, once that’s done, you’ve got a solid foundation on which to build the station.
“Spring for the mine shafts and summer for the actual construction. As ever in these things, the construction is relatively quick after all the preparatory pieces.
“The main message for resident is, this is no longer if but it is actually now definitely happening.
“The money is secure, the construction team is on the ground, the timetables are already in place for trains to be stopping here in future.”
He added: “(At Darlaston) You can see workmen on the ground so it is definitely happening as well.
“The really exciting thing about Darlaston is you can already see the prospect of the railway coming has brought other private sector investment. And that is what this is all about ultimately – bringing jobs and opportunities.”
Councillor Andrew said: “It is a fantastic thing for Willenhall and a new start where we can look to the future, creating a vibrant town where people have got opportunities for education, employment across the region.
“We launched the Willenhall Masterplan on the back of the delivery of the railway station because it’s a game changer and we’re determined to make sure all the derelict sites in Willenhall are brought back into residential or commercial use.
“People of Willenhall have been let down in the past and it shows this time with the railway station and the £20 million (Levelling Up funding) we are delivering for them.”