A convertible inflatable device includes a first inflatable bed, a second inflatable bed, a front chamber, a left chamber, a right chamber, and a rear chamber. The first inflatable bed is surrounded by the front chamber, the left chamber, the right chamber, and the rear chamber. The front chamber, the left chamber, the rear chamber, and the right chamber are connected to each other sequentially. A first end of the second inflatable bed is connected to the junction of the first inflatable bed and the rear chamber. The convertible inflatable device can be converted to an inflatable bed, an inflatable boat, an inflatable water slide or an inflatable recliner chair, and the conversion between any of them is mutual and convenient.