This paper introduces in detail the development of a micro pressure standard device for liquid pressure gauge calibration. Using ultrasonic liquid level positioning technology to realize accurate liquid level positioning, the height of liquid column is accurately measured by laser interference technology. At the same time, the temperature control, displacement control, data acquisition and processing subsystem design are introduced. Finally, the measurement uncertainty of the micro pressure standard device is analyzed and verified. The standard device fills the nonexistence of the standard below 5kPa micro pressure value and solves the traceability problem of high accuracy micro pressure instruments in national defense system.