The invention provides a plant water-storage and moisture-keeping device. The device includes a water collecting structure, a water storage structure and a soil spacing water seepage plate; the water collecting structure includes a vertical barrel-shaped water collecting cylinder of which the outer side wall is an inverted-boss shape, a water collecting hopper is installed in the water collecting cylinder, and the water collecting hopper is higher than the water collecting cylinder; the water storage structure includes a vertical barrel-shaped water storage cylinder of which the inner holes are stepped holes, the larger-diameter hole faces upwards, and the diameter of the large-diameter hole is matched with that of a smaller-diameter end on the outer wall of the water collecting cylinder; the water storage cylinder is internally provided with an inverted-hopper-shaped water storage hopper lower than the water storage cylinder, and a plurality of root system growth holes are formed in the wall of the water storage cylinder; the soil spacing water seepage plate includes a bowl-shaped support of a net structure, and the support is wound with super absorbent fibers. According to the water-storage and moisture-keeping device, thermal insulation, water retention and moisture keeping are achieved, nutrients and water required by the early-stage growth of plants can be met, the survival rate of the plants is ensured, and the requirement of bare surface ecological environment recovery after arid and semi-arid area bare surface and engineering construction are conducted is met.