The invention discloses an unsupported alternating curved tube dry type evaporator, which comprises a refrigerant inlet, a refrigerant outlet, a chilled water inlet, a chilled water outlet, a first end socket, a second end socket, a first tube sheet, a second tube sheet, a shell, a clapboard, heat exchange tubes and a bundling steel belt, wherein the heat exchange tubes are alternating curved tubes, and a ratio of the twist range and the equivalent diameter of each heat exchange tube is 6-12; the ratio of the short shaft and the long shaft of the cross section of the heat exchange tube 9 is 0.5-0.7; and the alternating curved heat exchange tubes are sequentially contacted with each other to be arranged, and are supported by self to form tube bundles depending on each contact point of the alternating curved tubes. The invention strengthens the turbulence degree of fluid in the tubes so that the fluid in the tubes can be fully mixed and the boundary layer is reduced, and strengthens the heat transfer. A shell side is not provided with baffles and can realize self supporting depending on the mutual contact of the alternating curved tubes, the fluid flows among the tubes are uniform, flow dead zones are eliminated, fouling deposit of the shell side is reduced, the heat transfer efficiency is improved, the service life of equipment is prolonged, and production cost is lowered.