A hydroponic cultivation apparatus with detachable cultivation tray is provided in that each cultivation tray is magnetically mounted to an expansion socket of a main aqueduct so that a replaceable cultivation room may be independently provided. Each cultivation tray is equipped with a light source plate at the bottom. The light source plate is provided with power via a wireless receiver connected with a wireless transmitter at the socket. Multiple drain slots are aligning along a direction perpendicular to a horizontal level on each cultivation tray with some of them plugged with insulation pieces so that each cultivation tray may have the water level controlled independently.