The invention relates to a poria cocos colloid with self-stabilization dispersibility in water and a preparation method of health food of the poria cocos colloid. The method is characterized in that the poria cocos powder is dissolved in a dilute aqueous alkali, acid is used for adjusting the pH value of the solution, and the colloid with self-stabilization dispersibility is finally generated. The generated colloid and various nutrient components are mixed to prepare the health food having different functions. All nutrient composition having pachymaran in poria cocos as a main part can be easily absorbed by human body, the poria cocos colloid with self-stabilization dispersibility is easily cooperated with various nutrients, and the usage of a food additive during health food processing is reduced.