In this study, we focus on the design of a wearable inertial navigation device that is based on a MEMS chip and a Bluetooth wireless transmitting module and that uses the object-controlling technology of the Unity game engine to write a game script for a treasure hunt in an ancient Chinese virtual reality (VR) world. The wearable device proposed in this paper utilizes an ATmega168 chip as the main controller, which cooperates with a three-axis accelerometer and gyroscopic sensor to detect the forward, backward, and rotating movements of game players. The movement data are transmitted to the Unity 3D game engine using Bluetooth, and the game software can then control the first-person character. The interactive elements between reality and the VR world combined as described in this paper can deliver a new experience to games, driving simulators, medical surgery, and even a variety of commercial situations. Experimental results show that the performance of the proposed wearable device is stable.