The invention discloses an intelligent fish tank with automatic cleaning and automatic water changing functions. The fish tank comprises a tank body. The tank body comprises a water inlet system and a drainage system, and a filter system, and is also provided with a filter device automatically cleaning a filter cloth. The fish tank is advantaged in that: 1, a central controller can determine clean state of the filter cloth according to inlet and outlet flow rate, so as to start a corresponding servo motor and a solenoid valve to automatically clean; 2, the fish tank can control cleaning condition of the filter cloth through controlling cleaning time; 3, the fish tank completely realizes automatic cleaning of the filter cloth; 4, the fish tank realizes to clean the filter cloth at regular time, and can automatically clean the filter cloth at any time through one key control; 5, the central controller can control through a remote control, and can control through a communication device of a mobile phone by a network, and can control by hand; 6, a water changing and drainage pipe is a downbuckle extension pipe and can adjust volume of water needed to be changed, and can be controlled to prevent to drain excessive water in the fish tank caused by misoperation, the upper part of the water changing and drainage pipe is provided with a one-way valve, blocking water from entering the fish tank from the drainage pipe when water is added to the fish tank.