A virtual reality system using mixed reality according to the present invention includes: a chroma-key environment booth in which a chroma-key screen is formed in a space corresponding to a viewing range of a user; a depth camera unit installed on an upper surface of the chroma-key environment booth and capturing the user and generating depth image information; an HMD device in which a stereoscopic camera worn on a head of the user and performing capturing at positions corresponding to both eyes of the user is positioned, and a head tracking marker is positioned on an upper end of the stereoscopic camera; and a mixed reality processing device detecting the head tracking marker positioned in the HMD device by receiving the depth image information and detecting position and rotation values of the head of the user in an actual environment.