The invention relates to an unblocking method for an oil-gas well. According to the blocking method, a composite unblocking agent composed of an agent A, an agent B and an agent C is used to conduct unblocking; components in the composite unblocking agent are injected into the oil-gas well in a time-division asynchronous mode through injection equipment at least provided with a storage unit, an injection unit and a control unit, wherein the agent A, the agent B and the agent C are stored in chambers of the storage unit in a separated mode, and the chambers inject the components in the composite unblocking agent into the injection unit in a pressurizing mode through injection pipelines; and the injection unit coupled with an wellhead comprises a main hole channel and at least one injection port provided with blocking valves used for controlling the jet rates of the components in the composite unblocking agent, and the injection unit jets and injects the agent A, the agent B and the agent C from the injection ports with the specified speed in a time division mode based on analysis of the control unit in gel viscosity in organic matters in the oil-gas well, water injection pressure, the liquid outlet amount and/or the water content.