Wu, 27, has widely been tipped to make a switch to Europe due to his incredible exploits in the Super League, which saw him dubbed the 'Chinese Ronaldo' by local media.
Having joined SIPG back in 2006, he became the youngest ever debutant at 14-years-old and netted his first professional goal at 16.
Since then, he's been instrumental in the club's rise from the third-tier to a maiden top-flight title last season.
Last season, the 65-time capped China superstar outscored the likes of teammate Hulk, Odion Ighalo, Cédric Bakambu, Graziano Pele, Nyasha Mushewkwi and Alexandre Pato, with 27 league goals in 29 games.
— RCD Espanyol (@RCDEspanyol) January 28, 2019
Now Espanyol have announced his arrival after weeks of speculation linking him with a move to Chinese-owned Premier League side Wolverhampton.
The length of the contract and transfer fee has yet to be disclosed but SIPG claim the financial aspect holds second preference over the development of the nations most prized asset.
"SIPG still follows one basic principle: as long as it (the transfer) is beneficial to the player's career and the development of Chinese football, the club will fully support it," SIPG said in a statement.
Overall, the talented winger scored 120 goals and registered 66 assists in 217 appearances for the Chinese Super League champions.