自由动作。
faq：
Can a character with Quick Draw and a base attack
bonus of +6 or better make a melee attack with one weapon
and a ranged attack with another weapon in the same
round? What if the melee weapon requires two hands to
wield?
...
This situation is actually improved if the melee weapon is a
two-handed weapon. A character can hold a two-handed
weapon in one hand; he just can’t attack with it while it’s held
like that. Thus, he wouldn’t even have to drop the weapon in
order to draw and throw the dagger. If Krusk the 6th-level
barbarian had Quick Draw, he could swing his greataxe (using
his full base attack bonus), then leave the axe in his off-hand
while drawing a javelin with his primary hand (free action), and
finally throw the javelin (using his base attack bonus –5). If
Krusk were drawing a ranged weapon that required two hands
to use (such as a bow), he’d have to drop his greataxe.
Can a creature make a slam or claw attack when both
his hands are used for something else, such as holding a
two-handed weapon?
As long as the creature can easily let go with one hand, yes.
A two-handed weapon requires two hands to wield in combat,
but not to hold. A frost giant could choose to make a slam
attack instead of a greataxe attack without having to drop the
greataxe.
...
