The present invention relates to a mixed reality system integrated with a surgical navigation system including a group of moveable position markers configured on a surgical instrument; a position sensor sensing the group of moveable position markers to acquire an instrument coordinate for the surgical instrument; a registered positioning marker configured in proximity to a surgical area to acquire a surgical area coordinate for the surgical area; a plurality of mixed reality sensors detecting the registered positioning marker and a plurality of mixed reality information; a computing unit module configured to receive the instrument coordinate, the surgical area coordinate, the plurality of mixed reality information, and a digital model of the surgical area, to render the digital model corresponded to the surgical area, and to add a digital instrument object into the digital model in accordance with the instrument coordinate; and a mixed reality display providing for a user to view and showing the digital model and the digital instrument object to the user upon the receipt thereof.