The invention discloses a multifunctional monitoring system used for a deoxygenating water tank. The multifunctional monitoring system used for the deoxygenating water tank comprises a water supply control valve, a water pump, a weight detecting unit, a parameter setting unit, a water level controller, a power detecting unit, a clock circuit, a heating temperature controller, wherein the water level controller analyzes signals detected by the weight detecting unit with combination of the sectional area of an inner cavity input by the parameter setting unit, and then obtains the required heating water level in the deoxygenating water tank accordingly, and the heating temperature controller analyzes data detected by the weight detecting unit and the power detecting device with combination of the initial temperature value and the target temperature value which are input by the parameter setting unit, then obtains the required heating time for water which is contained in the deoxygenating water tank and needs to be heated from the initial temperature to the target temperature accordingly, and controls a heater accordingly. The multifunctional monitoring system used for the deoxygenating water tank is simple in structure, reasonable in design, easy and convenient to operate, high in intelligent degree, good in using effect and capable of solving the problems that an existing monitoring system for the deoxygenating water tank is inaccurate in monitoring parameters of water levels and water temperature, low in control accuracy, relatively poor in using effect and the like.