It is hoped it will replace the widely used English-language screening test that is currently translated to the language of heaven.
The early research has been carried out on bilingual children aged between six and 11 in schools across Denbighshire.
Sian Lloyd, a Welsh-speaking third-year student at Bangor university, devised the new test, which identifies differences between dyslexic and non-dyslexic children who speak Welsh as their mother tongue.
It uses Welsh words with different vowel sounds that are pronounced in the same way, such as "pys" and "pur" and "lliw" and "cyw".
"The idea was to see what kind of errors non-dyslexics performed on these words and compare these with previously diagnosed dyslexics of the same age," said Dr Enlli Thomas, who has worked alongside Ms Lloyd at the university's centre for bilingualism.
"The results revealed both quantitative and qualitative differences across the groups, proving that some of these words would act as good predictors of dyslexia in Welsh in a screening test."
A standardised dyslexia-screening test for bilingual children has long been called for.
The research will be presented at a conference at Bangor university on June 10. Run jointly by the Centre for Bilingualism and the Dyslexia Research Department, it is open to all.