Disclosed is a power distribution monitoring and intelligent reactive power optimization integrated device, which is characterized in that: the device comprises a circuit breaker QF, a controller TTU and a compensating capacitor bank C, wherein, the circuit breaker QF is connected between the device and system three-phase lines of A, B and C in series, the circuit breaker QF is closed to cause the controller TTU to get to work; the controller TTU calculates the system reactive power by detecting the amplitude and phase difference of system three-phase voltage and three-phase current, compares the values with set input threshold quantity and cut-off threshold quantity, and controls the inputting or withdrawing of compensating capacitors C through a combination switch FK; and the compensating capacitor bank C is input or withdraws from the system in groups and phases under the control of the controller TTU. The utility model employs the working mode of balance on the spot, and can effectively reduce the electrical loss, increase the voltage qualification rate, and improve the reliability of equipment running.