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.

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The American, 32, looked set to take part after warming up on the range but he then withdrew on the first tee.
The US Open champion fell on the stairs and hurt his lower back on Wednesday.
"I'm playing the best golf of my life and to have a freak accident happen yesterday afternoon, it sucks really bad," said Johnson.
"I have been worked on all morning and obviously I can take some swings, but I can't swing full, I can't make my normal swing and I didn't think there was any chance I could compete."
The 15-time PGA Tour winner added: "I was wearing socks and slipped and went down the three stairs. The left side of my lower back took the brunt of it and my left elbow is bruised as well."
Johnson's caddie was placing the ball on his tee for him on the range, while coach Butch Harmon said pain hindered Johnson's rest overnight.
Shortly before his withdrawal, he progressed from hitting wedge shots on the range to fuller swings and his involvement looked likely as he made his way to the first tee for a scheduled 19:03 BST start alongside playing partners Bubba Watson and Jimmy Walker.
Johnson was a popular pick to win the first major of the year as a result of the fine form he has shown in 2017. He has won the past three tournaments in which he has competed - February's Genesis Open, and both the WGC Mexico Championship and WGC Dell Match Play in March.
As well as winning last year's US Open by four shots, he finished ninth at the Open Championship and tied fourth at the Masters.
BBC Radio 5 live correspondent Iain Carter
Johnson took until the very last second to make what must have been an agonising decision to pull out. He was standing on the first tee before making the toughest call of his career. It is a severe blow for the player who has dominated golf this season.
He arrived here off the back of three big victories and was a justifiable favourite. All that has been lost through his freak fall at his rental home and the damage done to his back.
A collection of manuscripts and notebooks which belonged to poet and novelist Edward Thomas are to be conserved thanks to a grant.
[NEXT_CONCEPT]
World number one Dustin Johnson is out of the Masters at Augusta National after suffering a back injury in a fall at his rental home on Wednesday.