The invention discloses a 1,2,4-triazole compound, salt thereof and applications of the compound and salt. The compound has a structural formula shown in the description, wherein R represents hydrogen, phenyl or substituted phenyl, and a substituted group of substituted phenyl is selected from carboxyl, an ester group, C1-4 alkyl, C1-4 alkoxy groups, C1-4 halogenated alkyl, C1-4 halogenated alkoxygroups, C2-4 alkynyl, halogen, cyano groups, acyl, nitryl or hydroxyl. The compound has high insecticidal activity for aphids, part of compound has the insecticidal activity for aphids equivalent tothat of a commercial insecticide dinotefuran, and the compound can be used for controlling lepidoptera pests, coleoptera pests, heteropteran pests, diptera pests, orthoptera pests and homoptera pests.