Current GPS positioning technology is widely used in mobile positioning system, but it has many limitations, such as in order to provide accurate three-dimensional positioning the system must receive the positioning data of four GPS satellites. Based on this, we propose an approach based on CDMA 1X Communications GPS and GPSOne with a combination of new mobile positioning system. At realization of the program in the system, we make scientific researches on the two-mode switch positioning technology and some the judging criteria that the need to consider, as well as dual-mode switch to overcome errors caused by the excessive Zero Shift Algorithm Design and Implementation.