The invention provides a condensation-prevention structure and an air conditioner, and relates to the technical field of air conditioners. The condensation-prevention structure comprises a sliding door, a front panel lining plate, a front panel, a reinforcing plate and a first seam allowance assembly, an air opening is formed in the front panel, the front panel is installed on the front panel lining plate, and the sliding door is in sliding fit with the front panel lining plate; the reinforcing plate is detachably installed at the inner side, close to the air opening, of the reinforcing plate,and the reinforcing plate is provided with at least one through thermal insulation cavity. The first stopping seam allowance assembly is located at the other side, opposite to reinforcing plate, of the air opening, and comprises a first seam allowance part and a second seam allowance part, the first seam allowance part is arranged on the front panel, the second stop part is arranged on the frontpanel lining plate, and the first seam allowance part cooperates with the second seam allowance part to shield gaps between the front panel and the front panel lining plate. By means of the condensation-prevention structure, the condensation problem of the air conditioner can be solved, it is guaranteed that the front panel and the interior of the air conditioner are dry, then the service life ofthe air conditioner is prolonged, and the user experience is improved.