A Canberra brothel madam who kept a Thai woman as a sex slave has had her jail sentence cut after an appeal.

In 2012 Watcharaporn Nantahkhum, 46, was found guilty by a jury of six charges including that she had kept one of her employees as a slave.

The victim had been recruited from Thailand and was made to service almost 700 clients to pay off a $43,000 debt.

Nantahkum was also found guilty of offences against a second woman.

She was sentenced to eight years and 10 months in jail, but she quickly appealed the severity of the sentence and today she won.

The ACT Court of Appeal cut her sentence by two years and dropped her non-parole period by more than a year.

She will now be eligible for parole in late 2015.