The invention relates to a preparation method in which a crude medicine formula mainly based on natural plants as components is prepared into a medicament containing active officinal components by applying a unique pharmaceutical idea and a technical means, and particularly relates to a preparation method of a capsule for treating cardiovascular diseases. The preparation method of the capsule fortreating the cardiovascular diseases successively comprises the following steps: 1. respectively smashing 60g of ligusticum chuanxiong, 60g of radix salviae miltiorrhizae, 200g of dalbergia wood and 80g of borneol into fine powder for later use; 2. decocting 120g of ligusticum chuanxiong, 120g of radix salviae miltiorrhizae, 180g of purslane and 180g of homalomena occulta twice with water, wherein the first decocting time is 1.5 hours, and the second decocting time is 1 hour, filtering, mixing filtrates, concentrating the mixed filtrate to obtain a clear paste with a relative density of 1.10-1.20 at the temperature of 90 DEG C, adding ethanol so that ethanol content is 60%, standing for 48 hours, filtering, and recovering ethanol from the filtrate to obtain a thick paste the relative density of 1.31 at the temperature of 80 DEG C for later use; 3. adding the fine powder except borneol in the step 1 into the thick paste in the step 2, evenly mixing, and drying at the temperature below 80 DEG C, and smashing; and 4. adding the borneol fine powder in the step 1, evenly mixing, and encapsulating to obtain the capsule for treating the cardiovascular diseases.