A data sensing device and a data sensing method thereof are provided. The data sensing device includes a compensation signal generator, a weighting operator and an arithmetic operator. The compensation signal generator receives a basic input signal and a plurality of reference weighting values, and generates a compensation signal according to the basic input signal and the reference weighting values. The weighting operator has a plurality of memory cells, performs a writing operation on the memory cells according to the weighting values based on address information, and the weighting operator generates an output signal by the memory cells by receiving a plurality of input signals. The arithmetic operator performs an operation on the output signal and the compensation signal to generate a compensated output signal.