The local government officials said the incident took place in the vicinity of Greshk district late on Wednesday night.
The officials further added that the militants had placed large amounts of explosives inside the vehicle with an aim to target the security forces.
The provincial government media office in a statement also confirmed the incident and the death of the bomber.
The statement further added that the security forces opened fire on the vehicle as the suicide bomber was attempting to ram the vehicle into its target in Awpashak area.
Helmand government said the area is under total control of the security forces and the security situation is currently stable.
The anti-government armed militant groups including the Taliban insurgents have not commented regarding the report so far.
This comes as the Taliban insurgents launched a coordinated attack using a similar tactic of detonating Humvee vehicles by storming the security posts in Greshk district last month.
However, the attack was repulsed by the Afghan security forces after almost 48 hours of heavy gun battle that left several insurgents dead.