The invention discloses a cherry tomato culture medium and its preparation method. The cherry tomato culture medium comprises the following substances (by weight): 65-80 parts of crop straw powder, 30-45 parts of soybean meal, 15-26 parts of peanut meal, 15-20 parts of spent mushroom compost powder, 14-20 parts of humic acid, 13-20 parts of algae powder, 20-26 parts of plant ash, 15-21 parts of fishbone dust, 13-18 parts of Styphnolobium japonicum wood dust, 9-16 parts of pine needle meal, 25-35 parts of poultry manure, 20-35 parts of peat soil and 10-16 parts of coal ash. The invention also provides a preparation method of the cherry tomato culture medium. The prepared culture medium is specifically a culture medium for growth of cherry tomato. Straw used for the prepared culture medium is rich in nitrogen, phosphor, potassium, calcium, magnesium and organic matters, etc. The culture medium produced by fermentation of natural raw materials meets crop growth and development requirements, has more excellent fertility than a fertilizer purchased in the market, is easier to absorb and has fast release speed of fertility. The prepared culture medium can be used to remarkably raise quality and yield of cherry tomato.