Position measurement of a Mars rover is important for engineering and scientific researches. This paper reports a method to carry out high precision positioning of the rover and orbit determination of the orbiter by using the same- beam VLBI between the rover and the orbiter and the orbiters ranging data. The calculation method of the differential phase delay and signal link of a Mars rover is analyzed. The measurement error of the differential phase delay caused by solar plasma, atmosphere, ionosphere and instruments is estimated to lower than 10 ps. As a successful example, in ChangE-3, the differential phase delay data between the rover and lander are obtained with a random error of 1 ps, and the relative position of the rover is determined with an accuracy of 1 m by using the same beam VLBI, which demonstrates the effectiveness of the method. In the case of the Mars rover and the orbit, the simulation analysis results show that the Mars rover position can be determined with an error of hundreds of meters and the orbit of the orbiter can be determined with an error of tens of meters by using the orbiter ranging and the same-beam VLBI differential phase delay data.