Around 30% of fuel energy was not utilized due to being taken away by exhaust gas in traditional internal combustion engines (ICE),Waste heat recovery (WHR) technology with high efficiency was hence the key to achieving energy conservation and emission reduction. Electromechanical compound turbocharging technology was one of the most potential WHR technologies based on the traditional turbocharging technologies. A detailed investigation of research progress on the electromechanical compound turbocharging technology was conducted. Different layouts and characteristics together with the potential applications of electromechanical compound turbocharging technology were first overviewed and analyzed. Then the research progress of matching method and control strategy of electromechanical compound turbocharging technology for ICE was discussed and the research state of main components including turbine, compressor and electric motor/generator (M/G) was analyzed. Finally, the advantages of energy conservation and emission reduction, development trends and technical difficulties for electromechanical compound turbocharging technology were summarized.