The invention relates to the automobile engine field, and aims at providing an engine timing shell connecting structure. The engine timing shell connecting structure comprises a cylinder body 5, a cylinder cover 6, a timing shell 7, and a lubricating pump chain tensioning assembly, wherein the cylinder body 5 is provided with a balance shaft chain tensioning assembly, and the timing shell 7 is connected with the cylinder body 5 and the cylinder cover 6; the lubricating pump chain tensioning assembly comprises a lubricating pump chain tensioning rail 8 and a lubricating pump chain tensioning rail bolt 9, the lubricating pump chain tensioning rail bolt 9 is used for connecting the lubricating pump chain tensioning rail 8 with the cylinder body 5, and the big end face of the lubricating pump chain tensioning rail bolt 9 is connected with the inner end face of the timing shell 7 in a sealed mode. The engine timing shell connecting structure is compact in structure, the first-order mode can be ensured, and the noise, vibration and harshness (NVH) performances parameter can be optimized.