Abstract: In order to investigate the property of “Transmicelle” a new lecithin tank mixing adjuvant, its physical characteristics were investigated by transmission electron microscopy (TEM) and laser particle size analyzer, and its synergistic effect in controlling rice planthopper was determined by bioassay and field trials. The results showed that “Transmicelle” contained round liposomes with a Z-average size of 129.5 nm. The bioassay exhibited that “Transmicelle” can increase the toxicity of sulfoxaflor by 1.67 times. Furthermore, the field trial results indicated that the control effect of sulfoxaflor was increased by 9.04%-41.77% with the “Transmicelle”. Compared to the normal dosage treatment without “Transmicelle”, no significant difference in the control effect was detected by adding “Transmicelle” if the amont sulfoxaflor was reduced by 40%. The above results illustrate that the “Transmicelle” of the lecithin tank mixing adjuvant can enhance the utilization rate of the pesticide by forming liposomes, which results in a synergistic effect.