The operation, carried out in cooperation with French police, led to the arrest of 26 suspects in Spain and 25 in France as well as "the liberation of 25 victims", a statement said.
"The victims, some of them minors, were recruited in their homeland with the promise of a job in Spain with a monthly salary of over €4,000 ($5,000)," it said.
The women were sent to Spain on fake visas and charged between €12,000 and €14,000 euros for the trip, part of which had to be paid before they left China.
Once in Spain, the rings seized the women's passports and kept them in tiny windowless rooms in Parla, a southern Madrid suburb.
The women were forced to work as prostitutes for at least a year and turn over 40 percent of their income, police said.
Police seized €3,500 euros and 15,000 Chinese yuan (€1,800) in cash as well as several weapons and four cars.
The two rings owned 11 properties with a combined value of around €2.75 million, the police statement added.