A new genus and new species of Saucrosmylinae (Insecta, Neuroptera) is described as Huiyingosmylus bellus gen. et sp. nov., based on a well-preserved forewing from the Middle Jurassic of Daohugou, Inner Mongolia, China. Huiyingosmylus gen. nov. is characterized by the large size of forewing, relatively wide R1 space with several rows of cells, anteriorly bent Rs, dense crossveins over the entire wing and undulate outer margin. A key to the genera of Saucrosymylinae is provided.