Abstract The third‐party remanufacturer (TPR) can cooperate with the original equipment manufacturer (OEM) and remanufactured products are sold by the OEM (i.e., the cooperation mode). The TPR can also sell remanufactured products individually to compete with the OEM's new products (i.e., the competition mode). Considering the issue of false information in remanufacturing supply chains and the TPR's limited capital, we build game models with blockchain to explore the TPR's optimal financing strategies under different co‐opetition mode selections. We find that a high blockchain usage prompts the TPR to finance from the OEM in the competition mode, while a low blockchain usage motivates the TPR to choose the cooperation mode and opt for a bank credit. Besides, we also find that the difference between the TPR's optimal profits of cooperation and competition modes increases with the interest rate.