A kind of dual-parameter sensor based on magnetic-fluid-coated nonadiabatic tapered microfiber (NTF) cascaded with fiber Bragg grating (FBG) is proposed and experimentally demonstrated. Simultaneous measurement of magnetic field and temperature is realized by monitoring the variation of NTF interference spectrum and FBG characteristic dip. In the magnetic field range of 0–18 mT, the highest magnetic field sensitivity can reach 1.159 nm/mT. The maximum temperature sensitivity is up to −1.737 nm/°C in the temperature range of 25-50 °C. The proposed magnetic-fluid-coated NTF interferometer cascaded with FBG will find extensive application prospect due to its high sensitivity, easy fabrication, compactness, strong robustness, and low cost.