Well washing fluid capable of quickly removing dead oil on pipe wall and well washing method thereof

The invention discloses a well washing fluid capable of quickly removing dead oil on a pipe wall and a well washing method thereof. The well washing fluid comprises the following components in percentage by mass: 30-70% of dimethyl ether, 10-20% of mutual solvent, 3-5% of dispersing agent and the balance water. The well washing method comprises the following steps: in the normal production process, injecting the well washing fluid into an oil sleeve annulus for soaking; and before underground operation, performing closed circulation in a well, discharging original liquid in the oil sleeve annulus, and replacing with a new well washing fluid. The invention provides the well washing fluid capable of quickly removing dead oil on the pipe wall and the well washing method thereof, so that the problems of low efficiency, long time consumption and high cost of a dead oil removing technology of an offshore oilfield in the prior art are solved, and the aims of shortening the operation time of removing the dead oil in