Starting from carbonic acid diethyl ester, a series of 1,2,4-triazole derivatives containing 1,2,3-thiadiazole were synthesized. Reactions were performed by microwave irradiation or ultrasonic irradiation as well as by conventional heating. The structure of title compounds was characterized by 1H-NMR, MS, and elemental analyses. The fungicidal activities of these compounds were tested in vivo. Most of title compounds exhibited good antifungal activity against Pseudoperonospora cubensis. Some of title compounds displayed moderate antifungal activities against Fusarium oxysporum, Pseudoperonospora cubensis, Sphaerotheca fuligenea, Corynespora cassiicola, and Xanthomonas axonopodis.