Aiming at the trust problem in the sharing economy, the blockchain technology is used to build a shared economic blockchain network based on the proof-of-stake(PoS) consensus mechanism to achieve de-trust and decentralization. In PoS, the blockchain user provides transaction fees to encourage the mining pool to recruit verifiers for block propagation verification. Both the blockchain user and mining pool can benefit from more verifiers, but get the higher cost. This paper studies the conflict of interest between the blockchain user and mining pool in PoS of the sharing economic blockchain network from the perspective of Nash negotiation, and weighs the transaction fee and the number of verifiers to construct the Nash negotiation game model. Then, the existence and uniqueness of the Nash negotiation solution in the Nash negotiation game model is proved, and the optimal decision of the blockchain user and mining pool is obtained. Finally, numerical examples are used to analyze the impact of the communication cost and the number of verifiers on the optimal decision-making and utility of the blockchain user and mining pool. The research results show that both the blockchain user and mining pool can benefit from lower communication costs. And the Nash negotiation game model can effectively solve the conflict of interests between users and miners in the sharing economic blockchain network and improve network efficiency.