The invention discloses a data storage device. According to the data storage device, a nonstandard three-wire serial communication circuit based on an I2C bus is adopted to amplify and shape the clocksignal and the data signal and then the signals are transmitted to the storage circuit to be stored; the data in the storage circuit is shaped and then output to an upper computer; compared with a two-wire serial mode adopted by an existing standard I2C bus communication circuit, namely a mode of connecting one input signal line and one output signal line in series, the data storage device has the advantages that data loss does not occur in long-distance transmission, the data transmission distance is greatly increased, the application range of I2C bus communication is greatly widened, and the reliability and stability of data transmission are good. Moreover, although a non-standard three-wire serial communication circuit is adopted, a data communication protocol of the circuit is consistent with a standard two-wire communication protocol, and the circuit can be directly applied to an I2C communication protocol, so that long-distance data transmission can be realized without designingspecial transceiving circuits at two ends of an IC (Integrated Circuit), and the complexity and the cost of the system are greatly reduced.