Ship exhaust gas testing is of great significance for the implementation of environmental protection regulations and the promotion of sustainable development. At present, the shipping industry is developing in a green and carbon-free direction, and the unique advantages of clean fuels in environmental protection are gradually becoming the mainstream of ship fuel transformation, but the use of clean fuels has caused some new emission problems, and new demand for exhaust gas detection is emerging, which in turn affects the applicability of existing testing methods and equipment. By analyzing the emissions of traditional fossil fuels and five new clean fuels, this paper proposes an emission detection list and points out the components that need to be tested outside the regulations. According to the location of exhaust gas detection, the detection methods of flue gas and plume were introduced, and the shortcomings of plume detection in unconventional emissions were pointed out. Eight commonly used gas analyzers were introduced, and the current gas analyzers were analyzed and evaluated from five dimensions: volume, applicable detection methods, types of components, detection time and accuracy, and finally the development direction of exhaust gas detection methods and equipment was prospected, and it was pointed out that miniaturization, intelligence and low power consumption will be the focus of the subsequent development of testing equipment. The review and research of existing ship exhaust gas detection methods will help guide the research and development of related testing equipment.