The invention discloses an engine hot end structure. The engine hot end structure comprises a turbine machine case arranged between a gas turbine outer ring and a combustion chamber machine case, a combustion chamber outer secondary flow channel is formed by space between the turbine machine case and a combustion chamber inner ring, a turbine machine case inner cavity is formed by space between the turbine machine case and a turbine end component, and a lubricating oil pipeline of a lubricating oil system and/or a gas pipeline of an air system is arranged in the turbine machine case inner cavity. A body of the turbine machine case is a rotation type turbine machine case, bumps are locally arranged on the part, corresponding to the lubricating oil pipeline and/or the gas pipeline, of the circumference of the body of the turbine machine case, the space of the turbine machine case inner cavity is locally enlarged through the bumps, and the radial size of the circumference part except the bumps is smaller than the radial size of the bumps. According to the engine hot end structure, the inner diameter of a combustion chamber can be reduced, and the outer diameter size of an engine can be reduced; and the intermediate diameter of a low-pressure turbine is increased, and the acting capacity of the low-pressure turbine is improved; and the axial length of a low-pressure shaft system of the engine is reduced, the dynamic characteristic of an engine rotor is improved, and the engine performance is improved.