Juma Mohammed Abdullah al-Kaabi, 65, was caught in a bomb attack that killed 11 others at the Kandahar governor's guesthouse on 10 January.
He had been receiving treatment for his wounds at a hospital in Abu Dhabi.
The Taliban denied being behind the attack, blaming it on "internal local rivalry".
"With great sadness and sorrow, we mourn the martyr of the nation and his duty, the righteous son Juma Mohammed Abdullah al-Kaabi, who gave his pure soul for the sake of humanity," the UAE's ministry of presidential affairs said in a statement quoted by official news agency WAM.
Another five UAE officials were killed in the blast in southern Afghanistan, along with six other people, including the deputy governor, two senior Afghan officials and two MPs.
Seventeen people were also wounded, including the provincial governor.
The UAE said the officials had been carrying out "humanitarian, educational and development projects".
Among the projects was signing an agreement with Kardan University, in the capital Kabul, to offer scholarships funded by the UAE.
The United Arab Emirates ambassador to Afghanistan has died from injuries sustained in a bomb attack in Kandahar province last month, officials say.