Contractors Galliford Try completed the piling and foundation works and will now focus their efforts on the framework.
It marks a major milestone in the development, which forms part of the city's £150 million transport improvement scheme.
Councillor Louise Miles, deputy leader and cabinet member for resources, said: "The railway station is a prime example of how our regeneration projects can help us relight the city, having been hit hard by Covid-19.
"It is creating more opportunities for young people, supporting our vital local businesses to give them confidence to get back on their feet and grow, and generating more jobs and learning opportunities.
"Working under strict Covid-19 safety guidelines, contractors, Galliford Try, have made excellent progress on the phase two works and it is a great sight to see the second part of our fantastic new railway station coming out of the ground.
"The completed interchange will connect train, tram and bus in one place and will ultimately provide a gateway to our city that we can all enjoy using – and be proud of."
The railway station is due to fully open in 2021, with final works starting to connect the station to the West Midlands Metro – which has already been extended down Pipers Row.
Part of the station was opened up at the end of May and was handed over to West Midlands Railway. Next steps on the project include lifting in floor slabs, block work for external walls, as well as cladding and the roof being introduced.
The current station includes six ticket vending machines, new British Transport Police offices, toilets, accessibility and baby changing facilities, three retail units ready to be fitted out, and train crew accommodation.
Completion of phase two will deliver three more retail units, as well as a customer waiting room and help point. Work has been split into two to ensure it doesn't impact on train services.
Jonathon Martin, who lives in the city, has been working on the project in his role as trainee planner with Galliford Try.
The 22-year-old University of Wolverhampton student said: “This is a great opportunity for me.
"Galliford Try are paying for my university fees as well as giving me time off to attend lectures and providing additional support while I’m studying.
"The potential is massive in Wolverhampton. The city is ripe for development and I’m learning from everyone."
West Midlands Mayor Andy Street added: "It is great to see the new Wolverhampton Railway Station taking shape and that rapid progress is being made.
"The station is part of the new city centre Interchange which will link with the bus station and our new Metro extension along Pipers Row, allowing commuters to seamlessly transfer between rail, bus and tram services.
"The railway station project is a game changer for Wolverhampton and a fine example of how partnership working is delivering for the people of the West Midlands."
The Wolverhampton Interchange Partnership is formed of Wolverhampton Council, Ion, West Midlands Combined Authority, West Midlands Railway, Avanti West Coast, Network Rail, Midland Metro Alliance, Canal & River Trust, and Black Country LEP.