Abstract: The sex pheromone of Spodoptera frugiperda (J. E, Smith), has the advantages of the safety to the environment and the natural enemies, and without insecticides resistance. Its active components included (Z)-dodec-7-en-1-yl acetate, (Z)-dodec-9-en-1-yl acetate, (Z)-tetradec-9-en-1-yl acetate, (Z)-hexadec-11-en-1-yl acetate, (E)-dodec-7-en-1-yl acetate and (9Z,12E)-tetradeca-9,12-dien-1-yl acetate. The novel, efficient and concise synthesis of S. frugiperda (J. E, Smith) sex pheromones has been achieved. The key steps of this synthetic approach involved Wittig coupling of aldehyde with functionalized phosphomium salt, the alkylation of alkynes, and Knoevenagel condensation reaction of malonic acid with propionic aldehyde. Furthermore, the Wittig reaction of hydroxy-bearing phosphomium salt and Knoevenagel condensation reaction were firstly applied to the synthesis of S. frugiperda (J. E, Smith) sex pheromones.