Micro-motion testing device of pneumatic emergency cut-off valve

The invention relates to a micro-motion testing device of a pneumatic emergency cut-off valve, and belongs to the technical field of chemical equipment, the micro-motion testing device comprises a three-way valve, a ball valve and a flow-limiting orifice plate, air outlets and air inlets of the three-way valve and the ball valve are sequentially communicated in series through air pipelines, and an air inlet of the three-way valve is communicated with an air outlet of an electromagnetic valve; a flow limiting hole is formed in the flow limiting plate and communicates with an air outlet of the ball valve. The pressure reducing valve and the electromagnetic valve are firstly closed, the ball valve is opened, gas in the executing mechanism slowly flows out of the flow limiting hole of the flow limiting hole plate, and at the moment, whether the pneumatic executing mechanism refuses to move or not is observed; the structure is simple, the manufacturing cost is low, the operation and maintenance cost is low, a flow