From the Wiki, Don't know if it's true :

"The best way to kill them is to parry their attacks with a shield and then use the 3 hit combo with Iron mace or Porcupine to deplete half of their health during the stagger. This doesn't work against the slower attack because it has a very low stagger duration.

Pickaxes are another good way to kill them because they are vulnerable to Pickaxe damage which means pickaxes deal 2.5x damage against them (0.5x comes from the Pierce damage). However slower attack speed, lower base damage and lack of hit combo means that Iron pickaxe will deal less damage than the maces. Pickaxes are also harder to use because the shield can't be equipped at the same time and requires manually switching the weapons. On top of that, pickaxes very easily get a 33% damage penalty when the attack hitbox intersects with the ground. This can be mitigated by doing jump attacks, having higher ground or standing very close to the target but it's not reliable."

- https://valheim.fandom.com/wiki/Stone_Golem