The utility model relates to a water washing system capable of feeding C4 and saving desalted water for a MTBE (Methyl Tertiary Butyl Ether) device, and the water washing system is mainly used for solving the problem in the prior art that wasting is caused by direct discharging of lots of desalted water in a C4 water washing system. The water washing system is characterized in that a pipeline at the bottom of a buffer tank is connected with a pump and then enters the upper part of a water scrubber, the lower part of the water scrubber is connected with a C4 feeding pipeline, the pipeline at the bottom of the buffer tank is connected with a valve B and a valve C, the pipeline at the bottom of the water scrubber enters the top of a washing water flash tank, the pipeline at the bottom of the washing water flash tank is connected with a valve blank, namely an upstream valve, a regulating valve and a downstream valve, and a closed circulation pipeline is connected between the valve B and the valve C on the pipeline at the bottom of the buffer tank and between the upstream valve and the regulating valve on the pipeline at the bottom of the washing water flash tank and is connected with a valve D and a valve E. The water washing system capable of feeding C4 and saving desalted water for the MTBE (Methyl Tertiary Butyl Ether) device can be used for saving desalted water and reducing the cost under the condition that a C4 raw material meets the reaction requirements.