The irrigation emitter is an important part of the drip irrigation system, the effect of energy dissipation is the main performance of drip irrigation system. In order to design emitters with more efficient energy dissipation, the hydraulic performance and energy dissipation effect of two-ways mixed flow emitter in drip irrigation were analyzed, and some problems were analyzed. A new emitter with narrow neck and changing flow function was designed, which was calculated and simulated by use the Fluent software, and was compared with the twoways mixed flow emitter. The results show that the emitter with narrow neck for changing flow will reduce the pressure more obviously. The emitter has three steps to reduce the pressure. In the contour of velocity, the flow velocity is lower by 6% at the outlet when the entrance pressure is at kept at the same value. But the anti-blocking performance is better due to the channel is wider. The new emitter improves the efficiency of energy dissipation.