The embodiment of the invention discloses a control method and device for airless injection of a leak-tightness oil injector. The control method comprises the steps that after an engine shuts down, when the rail pressure of the interior of a common rail pipe is excessively high, dynamic leakage, that is an airless injection method of the leak-tightness oil injector is used for discharging high rail pressure of the interior of the common rail pipe, specifically, a shut-down signal of the engine is responded, and whether the rail pressure of the interior of the common rail pipe is greater than apreset threshold value or not is judged according to a rail pressure signal; if yes, the condition that the rail pressure of the interior of the common rail pipe is excessively high is illustrated; and in order to prevent the influence brought by the excessively high rail pressure of the interior of the common rail pipe, the oil injector is controlled to conduct airless injection for pressure discharging, the oil injector is controlled to stop airless injection pressure discharging until a preset stopping condition is achieved, the purpose that after the engine shuts down, the excessively high rail pressure of the interior of the common rail pipe is discharged is achieved, when the engine is started again, the condition that impact of the excessively high rail pressure of the interior ofthe common rail pipe on parts and components of a fuel system influences the service life of the parts and the components is prevented, and meanwhile, high risks for halt maintenance brought by the excessively high rail pressure are avoided.