Engine body cooling water jacket

The invention relates to an engine body cooling water jacket comprising a main water inlet channel (1) and water cavities. The main water inlet channel (1) is cast in the engine body and arranged above the water cavities. The main water inlet channel (1) is communicated with the water cavities through upper water inlet channels (2) and lower water inlet channels (4) both above water tanks of the water cavities. The water cavities are serially communicated through at least two water tanks by serially-connected water channels (3), and water feed channels (5) are arranged on the lower portions of the water tanks of the water cavities. The engine body cooling water jacket is reasonable in structure and good in cooling effect, and meets design requirements better in use, and cooling water can be well circulated in the engine body.