Tjostolv Moland was found dead last month in the cell he shared with his fellow Norwegian Joshua French, starting a diplomatic fight to bring the body home.
The coffin containing the dead 31-year-old arrived in Norway last week.
The family is allowing the media to attend to funeral, but has asked them to be sensitive to mourners.
Moland and French were sentenced to death in 2009 for murdering their Congolese driver, since when they have been held in prison in the Congolese capital Kinshasa. The two men, who met when serving in the Norwegian army, claim he was killed by bandits. French remains in prison in Kinshasa.