The invention belongs to the field of cement clinker preparation, and in particular, relates to cement clinker and a preparation method and an application thereof. The cement clinker is prepared from the following raw material components in parts by mass: 60-80 parts of limestone, 10-15 parts of perlite, 10-15 parts of clay, 5-10 parts of steel slag, 5-8 parts of lithium slag, 5-8 parts of chromium slag, and 3-5 parts of fly ash. The raw material components are broken, ground, mixed evenly and calcined to obtain the cement clinker; the cement clinker is mixed with gypsum and ground to obtain cement. Based on traditional cement clinker raw materials, the steel slag, lithium slag, chromium slag, fly ash and perlite are added, and play roles in adding a seed crystal, improving the burnability of cement raw material and grindability of the cement clinker, shortening the clinker formation time and setting time and the like; the prepared cement clinker and the cement have the characteristics of low hydration heat, good water retention, strong heat preservation and frost resistance, high strength and the like.