High-speed railwaybelongs to complex system engineering, in which a series of keymechanics problems are involved. The present paper discusses threekey problems of solid mechanics existing in high-speed railwayengineering, i.e. wheel-rail rolling contact mechanics, fatigue ofhigh-speed train components and dynamic interactions betweenhigh-speed trains and infrastructures. The latest advances inthese research areas are reviewed as well as their applications tohigh-speed railway engineering. Some suggestions for futurestudies are offered based on the demand from high-speed railwayengineering practice.