The museum, owned by British Robert Taylor, was first opened in 2012 in the coastal city of Vung Tau, but had to be closed down in that year for personal reasons.
It now opens again at 98 Tran Hung Dao Street, displaying more than 2,000 objects including guns, swords, bows, crossbows from armies around the world.
A number of portable cannons used by ethnic groups in northern Vietnam in the 14th and 15th centuries are also among the objects to be on view at the place.
Besides, the museum also showcases hundreds of military uniforms from European countries in the 15th and 16th centuries, as well as Japanese samurai costumes.
Taylor said he also has around a thousand other objects kept in his store in addition to what is on display at the museum, which is not capable of showcasing all of them.
Moreover, he is also preparing to bring around 500 other military uniforms and ancient weapons to Vietnam.