The invention discloses a guide device for an air conditioner. The guide device comprises a first guide plate module rotationally connected with a first side of an exhaust port, and a second guide plate module rotationally connected with a second side opposite to the first side of the exhaust port. The guide device is configured as follows: in a refrigerating mode, the first guide plate module and the second guide plate module are in a first state to reach upward cold wind flowing direction; and in a heating mode, the first guide plate module and the second guide plate module are in a second state to reach downward hot wind flowing direction. The invention further discloses an air conditioner. In the guide device and the air conditioner, aiming at different working modes of refrigeration and heating, cold wind and hot wind are different in flowing directions through controlling unfolding states of the first guide plate module and the second guide plate module rotationally arranged on two opposite sides of the exhaust port in the guide device, so that the exhaust effect of the air conditioner is improved.