The interferometric fiber-optic gyroscope (IFOG) is widely used in the fields of inertial navigation and rotational seismology. A direct way to improve the sensitivity of the IFOG is to increase the length of the sensing fiber, but this increases the cost and size of the gyroscope. Here, we propose an IFOG based on mode-division multiplexing (MDM), which exhibits relatively high performance. The experimental results show that, the proposed IFOG is improved to twice as much in terms of sensitivity, angle random walk, and bias instability with the use of MDM. This research provides a novel, to the best of our knowledge, solution for the design and implementation of low-cost, high-sensitivity IFOGs, which could contribute to their application in a wider range of fields.