The quantum cryptographic conferencing (QCC) protocol, which distributes identical secure keys to user groups, is a crucial component of the quantum network. Previous experimental works have implemented the measurement-device-independent (MDI) QCC, of which the key rate in an $N$-user network scales as $R\sim O({\eta }^N)$. Building on the MDI QCC protocol, the asynchronous MDI QCC protocol theoretically integrates the mode-pairing scheme into QCC, significantly boosting the key rate to $R\sim O(\eta )$ in the ideal case, which is independent of the number of users, thus demonstrating greater application potential. Experimentally, in this Letter, we implement the three-user asynchronous MDI QCC network without phase locking by adopting the fast Fourier transform-based frequency difference estimation and the phase drift compensation technique. Finally, we achieve a key rate of about $4.470\times {10}^{-9}\mathrm{bits}$ per pulse under a maximum overall loss of about 59.6 dB. This Letter provides a scalable solution for the development of large-scale quantum communication networks in the future.

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• Quantum communication
• Quantum communication, protocols & technology
• Quantum cryptography
• Quantum optics