The invention provides a lithium ion battery positive electrode, and battery composed of the positive electrode. The positive electrode includes a positive electrode active substance and magnesium hydroxide hybridized with the positive electrode active substance; and the use amount of the magnesium hydroxide is 0.1-200% of the mass of the positive electrode active substance. The lithium ion battery made of the positive electrode effectively reduces the burning and blasting risks under acupuncture, impact and other adverse conditions, and has improved use safety.