The invention relates to a glass cleaning agent and a preparation method thereof. The glass cleaning agent comprises the following components in parts by weight: 1-10 parts of a surfactant, 2-6 parts of sodium bicarbonate, 5-15 parts of ammonia water, 15-40 parts of ethanol, 75-100 parts of a diluent, 5-12 parts of glycerol and 150-200 parts of deionized water. The glass cleaning agent has simple manufacture, has no corrosion to glass, is not iced, and can be widely applied in various types of glass and porcelain and in all seasons; the cleaning agent takes less time, and only needs spraying; moreover, the glass cleaning agent has good lubricating function, prevents glass damage caused by small particles during wiping, has no peculiar smell and can keep air fresh.