Differential transformer sensor is a kind of sensor widely used in industrial production site, because of the structural parameters that determine the output characteristics of such sensors, such as the number of coil turns, core diameter, skeleton material and geometry, etc., so it is more difficult to optimize the configuration of system parameters, in fact, high-quality materials and high-precision processing technology are selected to ensure excellent output characteristics. The sensing characteristics of (Fe50Co50)72B20Si4Nb4 Bulk Metallic Glass (BMG) as the core material of differential transformer displacement sensor were studied. The experimental results show that under the same conditions, the sensor using metal glass as the core has higher sensitivity, better stability, greater signal-to-noise ratio, and smaller iron loss at higher excitation power frequency ω. Moreover, the core made of metal glass has a small size, high resistivity and small eddy current loss, so the repetition rate of the current can be relatively high, which effectively expands the frequency response range of the sensor.