The database has been created to help investigators cope with the vast amount of images abusers typically amass.
It will help police forces quickly check images seized in raids and spot those showing children not seen before.
Forces in the US, UK, Canada, New Zealand and Australia are helping test the database.Finding victims
Called Project Vic, work on the archive is being co-ordinated by the US Department of Homeland Security and the International Centre for Missing and Exploited Children.
James Cole, a national programme manager at Homeland Security, said the project grew out of the realisation that there was huge duplication of effort among those investigating abusers and the material they trade.
That problem was particularly acute in the US where there were tens of thousands of local police forces and jurisdiction on some crimes shared across local, state and federal agencies.
"We have issues with deconflicting investigations and also big issues with the amount of data that we are seizing," Mr Cole told the BBC.
Across all the crime categories it investigates, Homeland Security seizes "petabytes" of data every year, he said, adding that it was a signature trait of abusers that they amassed large collections of images and videos.
The Project Vic approach uses technologies and software from companies such as Netclean, Hubstream and others to allow investigators to categorise known material. This allows them to concentrate on never-seen-before material and produce a unique summary or "hash" for each new item, said Mr Cole.
"The idea is to allow law enforcement to run data against hash sets that are immediately available through cloud services," he said. "They can interrogate that data in real time and know a lot of things about it very quickly."
Project Vic is also seeking to promote and get backing for a new standards-based image formatting system. This would generate hashes using an open protocol and should make it straightforward to exchange comprehensive sets of hashes domestically and internationally without having to touch or manipulate the data.Abusers typically amass large collections of images and videos
Finding unique images more quickly would help police and other agencies focus on victims and material that had never been seen before, said Mr Cole.
"When material is produced you hope to trace it back to an offender and stop them producing or having further opportunities to exploit the child," he said. "We are making great strides in how we do that."
Rich Brown from the International Centre for Missing and Exploited Children, said Project Vic would help work being done globally to tackle abuse crimes.
"Project Vic represents the largest movement of its kind to change the way investigators approach this crime set," said Mr Brown.
Among abusers, material had become a kind of currency, said Mr Cole.
"In well over 90% of our cases there's no money changing hands," he said. "It's the material itself that is highly desirable for offenders. Money does not come into play."
New material has the highest value among abusers and it was incredibly useful to spot it so investigators can focus their efforts on it and work towards freeing victims, he said.
"The way we identify and rescue these children is by putting all that related information together," he said.
Unfortunately, he added, there were also cases in which investigators made little headway and just had to watch victims grow up among abusers.
"Sometimes," he said, "the clues are just not there."