The invention discloses a ship exhaust 
system and a wet exhaust apparatus thereof. The wet exhaust apparatus is connected in the ship exhaust 
system, and comprises a main body 
pipe, a gas inlet 
pipe,a water inlet 
pipe and a gas 
exhaust pipe, wherein the gas inlet pipe and the water inlet pipe are disposed at a first end surface of the main body pipe, the gas 
exhaust pipe is disposed at a second end surface of the main body pipe; the gas inlet pipe is connected to an outlet end of a first 
smoke exhaust pipe, the water inlet pipe is connected to a first outlet end of a 
seawater discharge pipe;the gas exhaust pipe is connected to an inlet end of a second 
smoke exhaust pipe, a first 
elbow is connected to the gas exhaust pipe; and the first 
elbow is disposed in the main body pipe, and the endopening of the first 
elbow is disposed downward, wherein the distance between the bottommost position at the end opening of the first elbow and a centerline of the gas exhaust pipe is between a 
radius of the gas exhaust pipe and a half of the exhaust backpressure of a 
diesel generator. According to the ship exhaust 
system and the wet exhaust apparatus thereof, the 
discharge of 
black smoke is effectively reduced, the emission of atmospheric sulfides is reduced, and 
waves are effectively prevented from flowing backwards to influence the 
diesel generator.