Emergency oil drainage method

The invention relates to the field of airplane fuel system design, in particular to an emergency oil drainage method, and aims to solve the problem that in an emergency oil drainage system, adverse influence is caused to an airplane due to unbalance caused by pump valve failure. The emergency oil drainage method comprises the following steps: a controller monitors the fuel amount in four fuel tanks in real time; when the difference value of the first fuel tank and the fourth fuel tank is in the first preset time period and is greater than the first preset difference value, a first emergency oil drainage pump or a fourth emergency oil drainage pump is switched off; when the difference value of the second fuel tank and the third fuel tank is in the second preset time period and is greater than the second preset difference value, a third emergency oil drainage pump or a second emergency oil drainage pump is switched off. According to the emergency oil drainage method, unbalance is automatically treated through the controller, tedious operation of crew members can be avoided, the burden of the crew is relieved, the problem that the adverse influence is caused to the airplane due to unbalance caused by pump valve failure is solved, and the safety of the airplane is improved.