Abstract: The OBS data acquisition has the advantages of less receiver and longer distance between receivers and thus may receive both the press wave and shear wave at the same time. As far as imaging processing is concerned, OBS faces more challenges comparing to the conventional seismic data processing. This article focuses on the OBS p-wave data processing as follows. 1. Direct wave is used for OBS reposition to ensure the correctness of location and to lay a solid foundation for correct OBS imaging; 2. P component and z component are used for demarcating to make the two component data consistent on frequency, amplitude and phase for merging processing; 3. through the analysis of wave field to effectively separate upgoing and downgoing wave field data and use the wider range of imaging's downgoing data to do the mirror migration. Finally we can obtain OBS p-wave profiles with clear sea bottom imaging, high resolution imaging below the sea bottom, and more accurate images in migration position. The final section has wide frequency band, rich frequency information, and can provide a lithological interpretation of a hydrate layer without well with rich frequency information of stacked seismic data.