The invention belongs to the technical field of building curing and relates to a steam curing trolley for a tunnel arch wall. The steam curing trolley comprises travelling wheels, front end bottom beams, lower-layer vertical columns, an end rubber plate, an end connecting plate, connecting rods, a lower door beam, upper through beams, transverse-moving oil cylinders, steam generators, middle-layervertical columns, an upper door beam, upper-layer vertical columns, a longitudinal shed pipe, a heat preservation waterproof layer, a steam generator pipeline, a temperature sensor, a humidity sensorand a lifting oil cylinder. Compared with the prior art, steam curing can effectively prevent cracks, caused by the nonuniform surface temperature or surface humidity, of concrete in the cooling anddrying solidifying processes, the water using amount of steam curing is much smaller than that of spraying curing, waste of the water source is reduced, and accumulated water on a construction workingface in a tunnel is avoided; and the steam curing trolley is high in automation degree, so that the manual work amount is decreased to a great extent.