Police detained 12 suspected traffickers as well as 85 people who allegedly used false documents to board planes bound for Britain, law authorities said in a statement on Wednesday.
Members of the network contacted people in Albania who wanted to leave the impoverished Balkan nation and promised to find them jobs in Britain or Ireland, the statement added.
The interested candidates would make their own way to Spain, usually by passing through Turkey and Italy.
"Members of the group in Barcelona would take care of the hotel reservations, buy the plane tickets and guide the immigrants in the boarding process so as to avoid detection during police controls," the statement said.
The group would provide the immigrants with false passports, residency permits, driving licences and health cards claiming they were either Romanian, Italian or Greek.
The arrests were carried out primarily at Barcelona's El Prat airport, and at Madrid's Barajas airport and the main airport on the Mediterranean holiday island of Mallorca.
Police began their operation in November 2014 after detecting a significant rise in the number of passengers passing through Spain en route for Britain and Ireland.