The rapid development of blockchain token incentives provides a new perspective to solve the problem of insufficient motivation for user content creation, but it still faces many challenges in the actual implementation process. This paper takes Steemit, a knowledge community based on blockchain, as the research object.By collecting block data, this paper analyzes the situations and problems existed in the token incentive mechanism of community from two aspects, including incentive equality and knowledge contribution efficiency, thus revealing the problem of token incentive allocation monopoly. Moreover, this paper identifies the influence of token incentive allocation monopoly on user knowledge contribution. The results show that the token incentive distribution in the community is monopolized by a small number of top users, and the incentive distribution mechanism in the community cannot effectively reflect the users' knowledge contribution levels. The inequality of token incentives allocation results in the decrease of users' content production and content discovery levels.