<p>Due to the growing imbalance between supply and demand in healthcare services, Internet medical service has emerged and developed rapidly, gradually forming a dual-channel healthcare service mode that integrates both online and offline channels. Considering the potential for misdiagnosis and the varying severity of patients’ conditions, this paper constructs a healthcare service dual-channel supply chain comprising patients, offline healthcare providers and online healthcare platforms. Optimal pricing strategies of healthcare services within a two-way referral mode are derived under centralized and decentralized decision-making scenarios. We introduce cost-sharing contracts as a mechanism for supply chain coordination. The impacts of key factors on decision-making are explored, namely, the probability of effective diagnosis on online platforms, the probability of patients with mild conditions, and the referral service fees. Results indicate that both the optimal prices and expected profits of the online healthcare service channel and the dual-channel model increase as the effectiveness of diagnosis on the online platform improves. Compared to the one-way referral mode, a greater number of patients are directed to online channels, thereby enabling more efficient allocation of resources across the entire healthcare service market. Moreover, cost-sharing contracts can achieve Pareto improvement in the performance of the dualchannel healthcare service. Our study provides a theoretical basis for pricing decisions by members of the dual-channel healthcare service supply chain, facilitating the creation of greater profits and social value.</p>