Phytic acid, one kind of organic acid, was added into the electrolyte to enhance the corrosion performance and thermal stability of micro-arc oxidation (MAO) coating on TC4 titanium alloy. The effect of phytic acid on the coating formation, morphology, and performance was analyzed by scanning electron microscope, X-ray diffractometer, X-ray photoelectron spectroscope, and thermal shock experiments. Results show that the addition of phytic acid leads to the refinement of discharge microholes and improves the formation efficiency and phase structure of MAO coating. Through potentiodynamic polarization tests, it is found that adding phytic acid can significantly enhance the corrosion resistance of MAO coating. The corrosion current density decreases from 8.406×10^-5 A·cm^-2 to 2.580×10^-6 A·cm^-2 when the phytic acid concentration in electrolyte changes to 12 mL/L (optimal phytic acid concentration). Cyclic high temperature oxidation test results indicate that the thermal shock resistance and high temperature oxidation resistance of TC4 alloy are enhanced.