A computing-in-memory apparatus is provided, which includes a voltage regulator having an amplifier and a reference current source, a computing-in-memory array having a plurality of computing units and a detection circuit connected to each other. The amplifier has a current input and a voltage output and is connected to the reference current source, and the voltage regulator provides an output voltage for supplying to the computing-in-memory array. An output current of the detection circuit is inputted into the voltage regulator to compare with the reference current source of the voltage regulator, and then a negative feedback convergence or a negative feedback mechanism is executed according to the comparison result to regulate the output voltage supplied by the voltage regulator to the computing-in-memory array.