Funding was announced in 2019 but its construction and then the pandemic has seen the centre near Machynlleth unable to welcome visitors for 20 months.
The nature reserve has been best known for its family of ospreys.
But last month there were new arrivals in the form of beavers, released into the wild by naturalist and television personality, Iolo Williams.
The Dyfi Wildlife Centre, run by Montgomeryshire Wildlife Trust, was awarded £525,000 to improve the visitor experience at the popular nature reserve.
Visitors are able to watch cameras trained onto the osprey next and walk around the reserve.
Kim Williams from the centre said: “We have been busy behind the scenes, not just with putting the final touches to the Dyfi Wildlife Centre, but also beavering away with some new technology that will enable us to have a pre-booking system for visits to the new centre and Dyfi Osprey Project this season.”
This year saw the two Ospreys, Idris and Telyn arrive earlier than usual.
The ospreys have three eggs in their nest.