This study constructs a tripartite evolutionary game model composed of a small and medium‐sized enterprise (SME), a supervisory enterprise, and a bank for the inventory financing model. The effects of blockchain technology on rent seeking in supply chain finance are calculated with focuses on its mechanism and advantages in inventory financing from the theoretical perspective. The influence of the parameters on the evolutions is likewise determined. Results show that for high‐value financing business, compared with the traditional model, the bank's application of blockchain can accelerate the system to the stable state, in which the SME complies with the contract, the supervisor does not seek collusion, and the bank thoroughly investigates the relationships of enterprises, and the enhancement of blockchain's automatic monitoring capability does not lead to the bank's inaction on regulation. For low‐value financing business, in response to the problem of collusion between the SME and the supervisor for additional benefits in the traditional model, the bank can monitor fund transfers within enterprises and unauthorized pledge release through smart contracts embedded in the blockchain system to automatically detect joint defaults, and effectively avoid the negative stable state of the bank indulging in inter‐enterprise relations which triggers collusion to embezzle financing. In addition, the bank can enhance the robustness of inventory financing service and curb rent‐seeking behavior in the blockchain inventory financing through strict penalties on the supervisor for its violations, monitoring abnormal capital flows of the SME, confirming appropriate credit rate gap, and moderately raising the service value threshold.