Abstract: In this paper, the factors affecting the hammer price of yellow diamonds were explored and analyzed through the auction data of yellow diamonds from July to September 2019 of Ali Auction. After constructing a five-factor model including auction setting, item description, commodity attribution, buyer competition and bidding strategy, the relevant hypothesis was put forward, and the empirical test was carried out by using correlation analysis and multiple linear regression analysis. It was found that the mark-up range in auction setting, the weight and colour grade of the diamonds in commodity attribute, the bidding times in buyer competition and the jumping bid in bidding strategy all have significant effects on the hammer price. Other factors such as margin, the number of pictures, the status of the end of the auction, and the number of applicants etc. have no significant impact on the hammer price.