In drip irrigation design, calculation method of emitter local resistance coefficient is different with different arrangements and the local resistance interaction is existed under some conditions. Local resistance interaction of emitters was appeared when the emitter spacing was less than a critical value, at this time, the emitter local resistance was different from local resistance in independent emitters. Local resistance coefficient would be calculated separately with different methods and different emitter spacings.Based on this, water filling tests of 16 drip pipe with six kinds of emitters spacings were conducted to investigate the interaction of local resistance in trickle laterals of online emitters. Meanwhile, the CFD software was applied on numerical simulation and verification. On this basis, 20 drip pipeswere simulated. The results showed that the simulatedvalues were in agreement with the experimental values for local resistance interactive coefficient of emitters. The local resistance interactive coefficient reduced with the decreasing emitters spacing. The changes of disturbance range and velocity distribution near the emitters were the main reasons for local resistance interaction in trickle laterals. Local resistance interaction of emitters should be taken into account when the emitter spacing was less than 0.5m. In this case, the values of interactive coefficient were varied from 0.9 to 1.0.