An automatic vessel access device based on real time volumetric ultrasound is provided. The automatic vessel access device comprises a probe configured to generate a VOI image of a candidate vessel in a real time volume ultrasound scan mode, a control device coupled to the probe, and at least one motor coupled to the control device. The control device comprises at least one processing module configured to determine at least one control parameter based on the VOI image, and a driver module coupled with the at least one processing module and configured to drive the at least one motor to automatically access the candidate vessel according to the at least one control parameter.