The invention relates to polyvinylpyrrolidone modified bone cement and a preparation method thereof. The polyvinylpyrrolidone modified bone cement is prepared from powder and a curing solution, wherein the powder is calcium sulfate hemihydrate, the curing solution is a polyvinylpyrrolidone water solution, the concentration is 0.1%-5%, and the solution-solid ratio is 0.4-0.6 ml/g. The polyvinylpyrrolidone curing solution with the concentration of 0.1%-5% is prepared; then, the calcium sulfate hemihydrate powder is added according to the solution-solid ratio and is mixed and stirred evenly, andthe injectable bone cement is formed through curing at room temperature. Polyvinylpyrrolidone is a high-molecular polymer water-soluble very easily, is odorless, tasteless and non-toxic almost and hasgood biocompatibility and stronger bonding property. The bone cement has good biocompatibility and biodegradability and can be used for filling and repairing of various bone defects and applied to the field of tissue engineering and medicine.