Research on diesel engine combustion characteristics in plateau environment can help disclose the influencing mechanism of plateau environment on working process and improve the performance of diesel engine in plateau environment. The overall situation of diesel engine combustion characteristics was reviewed. The rules for the influence of plateau environmental condition on combustion process and the optimization of plateau combustion for diesel engine were summarized. Then the research trend of diesel engine plateau combustion characteristics was put forward. Up to now, the research target has been changing from power recovery of single point to comprehensive performance improvement of full working conditions at variable altitudes, the research content has been changing from macroscopic rule to microscopic process, and the research direction has been changing to turbocharging technologies at varying altitudes.