The 18-year-old joins the Spanish third division club after scoring 31 goals in 16 games for Chesterfied FC's, based in England, youth development side.
"This is a magnificent achievement but it has come from dedication and hard work and people that have supported me and this is the beginning of a long journey ahead," Wong said on his instagram account.
"Also this all would not be possible if not for the friends that helped me make my first steps into Europe."
Wong said he aimed to be part of the first team, who play in La Liga, by the beginning of 2017.
Espanyol B are currently in 14th position in their Segunda B group.
