To address the problems of low echo signal-to-noise ratio ( SNR) and Lorentz force failure in the online monitoring of fiberwrapped gas cylinder by electromagnetic acoustic transducer (EMAT), an attached EMAT shear horizontal (SH) guided wave detection method based on coding compression is proposed. Through finite element modeling, the effects of Barker code sequence bits and subpulse carrier period, chirp signal pulse width and band width, combined Barker code combination on pulse compression signal SNR and resolution are analyzed and evaluated experimentally. Finally, the 20 mm×0. 5 mm×2 mm crack defect of the fiber-wrapped gas cylinder is detected. The results show that the metal attached method can effectively solve the problem of EMAT failure in non-metallic materials. Increasing the sequence bit and carrier period of Barker code, increasing the chirp pulse width, decreasing the chirp band width, and increasing the sequence length of combined Barker code can improve the SNR of pulse compression signals. After optimization design, compared with the traditional Tone-burst excitation method, the SNR of defect echo can be improved by at least 20. 4 dB by pulse compression technology. Among different coding algorithms, chirp signal excitation has the highest SNR, reaching 23. 9 dB. When 3 × 13-bit combination Barker code is adopted, the main lobe width of pulse compression signal is 28. 8 μs. The resolution is highest, but the SNR is low.