This invention involves a marine ship flue gas scrubbing equipment and scrubbing method. The equipment includes a shell with an upper scrubbing section and a water tank in the lower section. A smoke pipe leads in exhaust gas to an area between the scrubbing section and water tank. Scrubbing seawater is injected through an inlet above the scrubbing section, and a cooler is located along the pathway of the exhaust gas. The method of scrubbing includes leading-in exhaust gas, cooling the exhaust gas, injecting scrubbing seawater, performing scrubbing operation, and discharging clean gas. Embodiments of the invention provide a highly efficient scrubbing equipment and method suitable for high-temperature exhaust gas within a limited usable space. The methods and equipment are highly effective for emission reduction, has low energy consumption, small size, and long life performance.