A new 1,2,3-thiadiazole compound was synthesized and characterized by H-1 NMR, MS and HRMS. The crystal structure of the title compound (C12H11ClN2O4S2, Mr = 346.80) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P-1 with a = 8.4425(17) angstrom, b = 8.9801(18) angstrom, c = 9.859(2) angstrom, alpha = 84.36(3) degrees, beta = 86.71(3)degrees, gamma = 83.25(3)degrees, V = 737.9(3)angstrom(3), Z - 2, F(000) = 356, Dc = 1.561 g/cm(3), mu = 0.557 mm(-1), the final R1 - 0.0380 and wR2 = 0.0982 for 2160 observed reflections with I > 2 sigma(I). A total of 12585 reflections were collected, of which 2601 were independent (Rint = 0.0364). The herbicidal activity of title compound was determined, the results showed the title compound displayed excellent herbicidal activity against Brassica campestris.