The invention provides a water-cooled vertical engine, which includes: a crankshaf disposed substantially vertically, a cylinder block, a cylinder head, a cylinder block cooling water jacket forming in the cylinder block, a first automatic heat regulator for controlling the flow quantity of the cooling water in the cylinder block cooling water jacket, a cylinder head cooling water jacket forming in the cylinder head, and a second automatic heat regulator for controlling the flow quantity of the cooling water in the cylinder head cooling water jacket. Wherein, the cylinder block cooling water jacket has a cooling water outlet connecting with the first automatic heat regulator, the cylinder head cooling water jacket has a cooling water outlet connecting with the second automatic heat regulator, these cooling water outlets are close to each other. The engine also includes: an automatic heat regulator chamber with the first and second automatic heat regulators, and a member connecting with the cylinder block and cylinder head which have two cooling water outlets for forming the automatic heat regulator chamber. A common cooling water drainage component for the first and second automatic heat regulators is connected with the member at ther outer positions of the cylinder block and the cylinder head.