Plant cultivation device and method capable of automatically supplying water and fertilizer

The invention discloses a plant cultivation device and method capable of automatically supplying water and fertilizer. The plant cultivation device comprises a water storage tank for storing water, acultivation container for cultivating plants, a water diversion structure, a water level controller and a fertilizer storage container, wherein one end of the water diversion structure extends into the water storage tank, the other end of the water diversion structure extends into the cultivation container, and the water diversion structure is used for introducing water in the water storage tank into a cultivation substrate of the cultivation container; the water level controller is disposed in the water storage tank, the water level controller is connected with an external water supply devicethrough a water inlet pipe, and the water level controller is used for controlling the water level in the water storage tank; and the fertilizer storage container is used for storing slow release fertilizer or controlled rele