Sand-oil-water-gas pipe flow is common in the chemical and petroleum industries. In this paper, the identification of the solid phase in sand-oil-water-gas bubbly flow was investigated using a vibration-sensing method. Four identical high-frequency vibration sensors were selected to obtain the multiphase flow signals around the exit of a pipe elbow. Typical frequency-domain, mutual coherence, time-domain statistical, and time-domain joint analysis methods were applied for sand-vibration signal identification and characterization. Verification experiments were performed, and good agreement was found between the sand concentration (0.05-0.25 wt.%), particle size (96-180 mu m) and vibrational energy in water-gas bubbly flow and oil-water-gas bubbly flow. Sand characteristic frequency bands of 14-15.39 and 15.63-16.09 kHz for water-gas bubbly flow and of 14-16.45 and 19.31-20 kHz for oil-water-gas bubbly flow were found. Sand particles were more easily identified by varying the water velocity than the gas velocity. The validity of the detected sand signals was also verified using an acoustic sensor. It was proven that the vibration-sensing method can be used to characterize solid particles in oil-water-gas bubbly multiphase flows, laying the foundation for solid identification in more complex multiphase flows. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.