A single and double-decker variable recreational vehicle, comprising a regular carriage (1) and an upper carriage disposed above the regular carriage, the top panel (7) of the regular carriage serving as the bottom panel of the upper carriage. The upper carriage comprises a top roof (2), a top roof side skirt (3), a bottom panel upper skirt edge (9), a top roof lower skirt edge (10), and a foldable side fence (6). The recreational vehicle is also provided with a single and double-decker conversion system, which comprises a plurality of vertically disposed lifting support devices. The lifting support devices are each at least composed of a main body (4) and a lifting column (5) and are symmetrically distributed on both sides of the vehicle body of the recreational vehicle. The main body is fixedly connected to a side fence frame of the regular carriage. The lower end of the main body is connected to the vehicle body chassis of the regular carriage, and the upper end of the main body is connected to the top panel of the regular carriage. The lifting column is retractably inserted into the interior of the main body. The upper end of the lifting column is connected to the top roof of the upper carriage. The main body has an extending segment that protrudes from the bottom panel of the upper carriage. The functions of a house and a vehicle are fused by means of single and double-decker conversion, thus costs are low and said vehicle is economical.