Automatic switch jet element had many advantages and could be applied to lots of fields. Therefore, it was necessary to develop it. In order to research influence law of structural parameters to automatic switch performance, lots of experiments was done by changing split shape, split height, nozzle width and depth of traditional jet element. The jet could switch automatically when split shape was concave, split height was less and ratio of depth to width was larger. Automatic switch jet element was designed based on influence law of structural parameters to jet switch. The groove on the element sidewall, which was connected with the signal channel, was processed to break the swirl from the element work room and this was beneficial to realizing automatic switch. In addition, automatic switch would not achieve until the jet in the signal channel and controllable path was enough. For some jet element, automatic switch would be easier to realize when the flow became larger.
