There is no definitive answer to this question as it depends on a number of factors including the type of gun safe, the basement itself and your personal circumstances. That said, there are some pros and cons to consider before making a decision.
On the plus side, putting a gun safe in the basement can help to protect your firearms from fire or flood damage. Basements are typically cooler than the rest of the house, which can also help to prolong the life of your guns. Additionally, having a gun safe in the basement may deter burglars from targeting your home, as they would need to break into the basement first.
However, there are some potential drawbacks to consider as well. If your basement is damp or humid, this could rust or damage your guns over time. Additionally, if you have young children in the home, you'll need to take extra precautions to ensure that they cannot access the gun safe (such as keeping it locked at all times).