Over the past decades, Raman spectroscopy has been proven to be a powerful tool for in situ detection in the deep sea. However, two important issues are usually presented for solid detection of Raman in the sea: (a) The implementation of accurate laser focusing using the manipulator of remotely operated vehicles is difficult; (b) it is challenging to recognise minerals by Raman only. In this study, a novel approach was presented to address these difficulties by introducing microimage into underwater Raman system to aid laser focusing and spectra analysis. The further evaluation results showed that, using 5Â objective lens, the joint system could obtain the focused laser spot size of 290 μm on the focal plane for Raman detection and the spatial resolution of 2.2 μm for the microimaging. With the aid of microimaging, the Raman probe was successfully applied to the China Yellow Sea (36.129 N, 120.215 E) for in situ detection on the seafloor. Microimaging is a practical method of promoting the detection ability of underwater Raman spectroscopy, and biological applications would be another perspective in the future.