Cardiff University is currently exhibiting some of its collection as part of a three-day event to mark the centenary of Thomas' untimely death.
But Alan Hughes, head of special collections and archive, said some other items were in poor condition.
The National Manuscripts Conservation Trust has awarded them almost Â£3,000.
The university holds the largest archive of Thomas' letters, diaries, notebooks, poems, photographs and personal belongings.
Mr Hughes said the grant had allowed us it to "collaborate with Glamorgan Archives to undertake essential conservation work on many of Edward Thomas' notebooks".
He said nine were in particularly poor condition due to acidification, fragile bindings and general deterioration over time.
"Many are unable to be handled without a high risk of further damage and are therefore inaccessible to scrutiny, celebration, digitisation and study," he said.
Thomas, known for his poems written as World War One raged across Europe, was killed in the Battle of Arras at Easter 1917, at the age of 39.
While he was born in England, Prof Katie Gramich who organised this week's event, said his parents were Welsh and he loved Wales.
She said his work was influenced by the time he spent walking in Wales and he felt "cheated of a Welsh identity".
The exhibition, which runs until the autumn, features previously unheard archive recordings of family and friends, interviewed by the university's Prof R George Thomas in 1967.
A collection of manuscripts and notebooks which belonged to poet and novelist Edward Thomas are to be conserved thanks to a grant.