The invention discloses a calcium-boron compound fertilizer. The raw materials of the calcium-boron compound fertilizer comprise the following components in percentage by weight: 43-70% of calcium chloride, 20-48% of sodium borate, 4-9.1% of citric acid, 0.2-2% of sodium citrate, 0.2-1.5% of EDTA-2Na (ethylene diamine tetraacetic acid-2Na) and 0.2-1.5% of sodium tripolyphosphate. The finished compound fertilizer product comprises the following components in percentage by weight: 15-24% of calcium and 4-10% of boron. The invention also provides a preparation method of the calcium-boron compound fertilizer, which comprises the following steps: (1) respectively weighing the calcium chloride, sodium borate, citric acid, sodium citrate, EDTA-2Na and sodium tripolyphosphate; (2) grinding every raw material into granules by using a grinder, and passing the granules through a 50-mesh screen for later use; (3) after grinding, respectively adding the calcium chloride, EDTA-2Na, sodium tripolyphosphate, and part of citric acid and sodium citrate into a V-shaped mixing machine with a jacket, and stirring for 20 minutes, wherein in the stirring process, the humidity is controlled at 1-2%, and the temperature is controlled at 120-150 Fahrenheit degrees; (4) adding the sodium borate, and stirring for 20 minutes while continuing keeping the temperature and humidity; and (5) regulating the pH value to 3-6 with the citric acid and sodium citrate. Calcium and boron in the fertilizer are scientifically proportioned to obtain the fertilizer with rich nutrients, and the fertilizer can be used for producing excellent fruits and crops.