The invention discloses an online monitoring method of turbine load fluctuation for jamming judgment of an adjusting valve. The online monitoring method comprises the following six steps of: (a) acquiring relationship between the stroke of an oil-driven machine and the openness of a valve of the adjusting valve of a turbine; (b) monitoring the operating state of the adjusting valve of the turbine in real time; (c) acquiring a position instruction of the adjusting valve in real time; (d) acquiring actual stroke openness of the adjusting valve in real time; (e) comparing the position instruction and the actual stroke openness of the adjusting valve, and judging whether jamming is caused; and (f) if the jamming is caused, alarming immediately to prevent the turbine load fluctuation from causing accidents of a unit or a power grid. The online monitoring method disclosed by the invention has the advantages that the in-advance prejudgment for the turbine load fluctuation accident can be realized, so that the safety and the stability of the unit and the power grid can be improved.