The body of Roy Blackman, 73, was found inside the property on Headcorn Road, Biddenden, at about 09:00 GMT on Monday.
A post-mortem examination revealed he died as a result of multiple blunt force injuries.
Kent Police said a 49-year-old man, from Maidstone, was detained on Wednesday.
The force believes the break-in took place sometime between 01:00 and 03:00 on Monday.
Several suspects, who had "targeted a vulnerable man", are being hunted, a spokesman said.
Det Insp Lee Whitehead said: "Mr Blackman was beaten to death in his own home in what appears to be a violent burglary.
"A safe is missing from the property and we are keen to locate it.
"I believe that several suspects would have carried out this crime. They have targeted a vulnerable man in his own home leaving a trail of devastation in their wake."
He described Mr Blackman as a "well-known and well liked member of the community", whose killing had left his family "distraught".
Detectives are particularly keen to speak to anyone who may have been in the area of Headcorn Road between Weeks Lane and Frittenden Road from 19:30 GMT on Sunday into the early hours of Monday.
A man has been arrested on suspicion of murder of a burglary victim who was beaten to death at his Kent home.