The invention discloses a method for preparing collagen peptide chocolate. The method comprises the following steps of: selecting collagen peptide with molecular weight of below 3,000 daltons as a raw material; throwing chocolate and the collagen peptide into a chocolate refining mill according to a weight ratio of the chocolate to the collagen peptide of 8:1; accurately grinding the chocolate and the collagen peptide at the temperature of between 35 and 40 DEG C for 7 to 9 hours; after the chocolate and the collagen peptide are accurately ground, placing the chocolate and the collagen peptide into a constant-temperature stirrer at the temperature of 50 DEG C to stir for 5 to 7 hours to remove bubbles; after the bubbles of the chocolate are eliminated completely; discharging cast mould; cooling and moulding; after the product is moulded, performing mold stripping and finishing; and weighing and packaging, in the step (4), the cooling and moulding conditions are that the temperature is 15 DEG C and natural cooling lasts for 10 hours. By the method, mouthfeel and nutritional ingredients of the chocolate are maintained; collagen needed by a human body is supplemented; energy and nutrients are supplemented at the same time; and the collagen peptide chocolate is convenient to eat.