Scott Ramsay, 27, was left critically injured after the smash on New Year's Day 2010, which killed Caroline Cumming.
The couple were walking in Dundee's Arbroath Road as they headed home from a Hogmanay party when Jamie Dolan, then 17, caused the accident.
Dolan had never been behind the wheel of a car before the crash, was two-and-a-half times the drink-drive limit and driving at 60mph in a 30mph zone at the time of the incident.
He was jailed in September 2010 for seven years.
Ms Cumming, 24, died after she was thrown almost 90ft by the impact. Mr Ramsay was left with extensive injuries to his leg, a fractured jaw and a ruptured bladder.
He is now taking legal action against Dolan at the Court of Session in Edinburgh. Solicitors say he will be claiming for damages in response to the severity of his injuries, plus damages for "loss of society" relating to his partner's death.