The state of emergency has been in place since the Paris attacks in November, and the extension would see the measures -- which give the police extra powers to carry out searches and place people under house arrest -- remain in place until the end of January 2017.
After seven-hours of at times tense debate, the parliament voted early Wednesday morning in favour of the law 489 to 26 -- the fourth time the state of emergency has been prolonged.
The National Assembly also voted to allow authorities to search luggage and vehicles without prior approval from a prosecutor.
The law now needs to pass through the Senate, which is set to vote on it Wednesday afternoon.
President Francois Hollande had last Thursday announced a plan to lift the emergency security measures, but changed tack hours later after a truck driver ploughed through a crowd at Bastille Day celebrations in Nice, killing 84 people in an attack later claimed by the Islamic State group.
Hollande's Socialist government has been under heavy criticism from the right for its response to the slew of extremist attacks.
The fact the president was open to the six-month extension was seen as a concession to opposition Republicans who have demanded that the state of emergency be maintained through to the end of the year.
With elections due next year, the political unity seen after last year's attack on satirical magazine Charlie Hebdo has evaporated.
Interior Minister Bernard Cazeneuve has defended the government, saying it has bolstered security notably by sending thousands of troops into the streets.