解答:(1)解:∵AA′⊥平面ABD,AA′=2,S△ABD= 1 2 S△ABC= 1 2 × 1 2 ×2×2×sin60°= 3 2 ,∴三棱锥A′-ABD的体积:V= 1 3 ×AA′×S△ABD= 1 3 ×2× 3 2 = 3 3 .(2)证明:∵正三棱柱ABC-A′B′C′中,D是BC的中点,∴AD⊥BC,AD⊥BB′,∴AD⊥平面BC′B′,又B′D?平面BC′B′,∴AD⊥B′D.