The invention belongs to the technical field of food processing and in particular relates to a pudding capable of moistening the lung and relieving a cough and a preparation method of the pudding. The pudding is prepared from mango leaves, hylocereus undatus flowers, dragon fruit, buffalo milk, a thickener and xylitol as raw materials, and also various vegetable and fruit particles can be added. The pudding is prepared by combining ingredients of natural Chinese herbal medicine plants, does not have toxic or side effects, is low in sugar content, free of essence and pigment, convenient to eat and definite in healthcare effect, and has the effects of clearing heat and toxic materials, relieving swelling and pain, clearing throat-heat, moistening the lung, relieving the cough, reducing sputum, relaxing bowels and the like; xylitol is adopted for replacing conventional white granulated sugar to serve as a sweetener; moreover, the fruit and vegetable particles are added, so that the pudding has the specific fresh and sweet tastes of natural fruit and vegetable plants. Therefore, the pudding is suitable for daily prevention and healthcare of various people, has good prevention and healthcare effects, fills up the blank of pudding products in the market, and can meet the requirements of different markets and people.