The invention discloses a three-dimensional-model-based measuring device comprising a first guide rail (2), a second guide rail (3), two internal cameras (10), and two external cameras (27). The two internal cameras (10) are connected to the first guide rail (2) in a translatable and rotatable manner and correspond to the two eyes of the user; and the external cameras (27) are connected to the second guide rail (3) in a translatable and rotatable manner and correspond to the two eyes of the user. According to the three-dimensional-model-based measuring device, the good three-dimensional modelmeasurement result, real stereoscopic vision and immersive augmented reality experience can be obtained when the user moves the eyeballs; the user is able to measure a measured object precisely by using the three-dimensional model and carry out virtual operation on the three-dimensional model precisely in an augmented reality scene; and with adjustment of the center of gravity of the device, the user experience is improved when the user wears the device for long time and the injury on the body of the user by the device is avoided.