The invention discloses a small-scale high-efficiency and labor-saving watermelon cultivation method which comprises the following steps: making planting ridges; laying mulching films and dropper zones; planting watermelon seedlings; building an arched shed; forming holes in shed plastic films; performing field management. The arched shed support is made by adopting glass fiber pipes, only a layerof shed films is used, one-time permanent ventilation is performed in a manner of forming holes in the shed films at the later stage, the investment is less, and the operation is simple. According tothe method disclosed by the invention, small watermelons are basically located in a stable growth environment in the early growth period, the condition that the plant growth is influenced due to temperature fluctuation caused by ventilation in the general arched shed cultivation manner is avoided, the watermelons grow in a rainproof environment at the later stage, the plants are healthy and strong, the growth speed is high, the diseases and cracking fruits are decreased, the watermelons can appear in the market in advance, the commodity nature of the watermelons is excellent, and the benefitsare high. The watermelons are covered by green plastic films, the effects of inhibiting weeds and maintaining the temperature and humidity can be achieved, and the phenomenon that leaf sunburn is caused by strong light in summer can be avoided.