Blockchain IP(intellectual property) traceability is becoming a hot topic in current research. In order to explore the impact of blockchain traceability on the decision-making of licensed and licensed manufacturers after IP licensing under the background of 'grey market'(also known as parallel importation, which referred to the entry of genuine products into another country without the permission of the IP owner), this paper constructed a Stackelberg game model for a single-oligopoly market based on the method of game theory analysis, which was solved by the backward induction method. It solved the game model by applying the inverse induction method. The results show that in the absence of grey market, when IP licensing was in the early stage, the leading manufacturer's willingness to implement blockchain for IP traceability is not strong, but when IP licensing was in the middle stage, the willingness of blockchain for IP traceability gradually increases; and in the presence of grey market, the leading manufacturer could only motivate the enterprise to implement blockchain for IP traceability by adjusting the unit of IP licensing fee to be distributed to manufacturers, which reduced the leading manufacturer's blockchain for IP traceability. IP, reducing the cost of blockchain traceability for the leading manufacturer, and at the same time benefiting the profits of both parties. The numerical analysis reveals that, in the presence of a gray market, failing to adopt blockchain tra-cing can hurt manufacturers' profits, whereas adopting blockchain, though not eliminating the harm entirely, can mitigate its impact. IP licensing fees rise in response to parallel imports and blockchain costs. Manufacturers need to adjust their blockchain adoption strategies flexibly based on the discount value of the gray market. The conclusion is as follows: when there is no parallel import(grey market), the leading manufacturer always has an incentive to license IP and decide its blockchain traceability strategy based on the cost of adopting blockchain; when the parallel imported IP product(grey market) enters into the market, the leading manufacturer can decide its IP licensing and blockchain traceability strategy by observing the discounted value of the parallel imported product.