The disaster that occurred on Saturday evening claimed a person named Wahid of Parigi Moutong District when he was crossing the road.
The victims body has been evacuated to the nearest hospital and taken by his family.
The 18 injured people have been treated in hospital.
The landslide was caused by heavy rain on Saturday evening that poured the highway which is prone to landslide.
Governor of Central Sulawesi Longki Djangola expressed his condolences over the victims of the incident.
Longki has instructed related agencies to repair the highway that connects Palu city and Parigi Moutong District.
The regional administration predicted illegal logging in Kebun Kopi area as the cause of the disaster.
The government has warned people to be more careful when crossing the highway.
Several traffic signs have been installed in the area that is prone to landslides.
Police officers implemented an open-close traffic system as part of the road is still blocked by soil.