Marine ammonia gas emptying and recycling system

The utility model provides a marine ammonia gas emptying and recycling system which comprises an ammonia fuel cabin safety valve, an ammonia fuel supply pipeline safety valve, an ammonia gas liquefying tank, an ammonia gas absorbing device, a nitrogen inlet control valve, an ammonia gas detector, an ammonia gas output control valve and a bypass control valve which are connected with one another, ammonia gas in an ammonia fuel cabin or a supply pipeline is re-liquefied and recycled, so that a large amount of vented ammonia gas in a supply system is recycled again, and the utilization rate of fuel is increased; a small amount of residual ammonia gas is treated through the ammonia gas absorption device, so that the emptied gas reaches the waste gas emission standard, and the harm caused by direct emission of the ammonia gas to the atmosphere is reduced; and the ammonia gas absorption device is only used for treating a small amount of residual ammonia gas, so that the consumption of an ammonia gas absorbent or an