Abstract: Love-type wave is widely used in current in-seam seimic(ISS).From the analysis of construction and data processing, the author finds that Love wave has some limitations in the exploration process, while vertical component (z component) of Rayleigh-type of ISS has certain advantages over Love-type and can be used in ISS. In order to study its feasibility, the generalized Snell's law was analyzed and proved by theoretical calculation that Rayleigh wave existed under normal circumstances. The energy of z component of fundamental Rayleigh wave is strongest in the central position of coal seam and is not affected by receiving angle. Then, two-dimensional numerical simulation is used to analyze the propagation and energy distribution of Rayleigh wave in coal seam. It is found that the fundamental Rayleigh wave develops well, and the energy in the central position of coal seam is the strongest, which is consistent with the previous theoretical analysis. Finally, the application experiments of channel wave transmission exploration and reflection exploration are carried out. Rayleigh type wave processing method is used in data processing, and good detection results are obtained. The results show that Rayleigh wave usually exists, and because the elastic wave excited by explosive source is mainly P wave and the z component energy of Rayleigh wave is stronger than that of Love wave, Rayleigh wave is more suitable for ISS, which is manifested in the fact that compared with Love wave, Rayleigh wave has the advantages of high construction efficiency, portable equipment and construction time can be reduced to 1/3 or even 1/6 of the previous time; In the data processing stage, the rotation operation of two-component records is avoided, which simplifies the process and improves the processing accuracy.