The invention discloses a prime group, probe group and kit for detecting Kras gene mutation. The prime group comprises forward primers, reverse primers and probes which are used for detecting 7 Kras gene mutation types, wherein the forward primers respectively are 34A-Rev-Fp10, 35A-Rev-Fp4, 38A-Rev-Fp13, 34C-Rev-Fp, 34T-Rev-Fp, 35C-Rev-Fp and 35T-Rev-Fp, the reverse primers are Kras-Rev-Rp, and the probes respectively are 34A-Rev-Pb4, 35A-Rev-Pb2, 38A-Rev-Pb3, 34C-Rev-Pb, 34T-Rev-Pb, 35C-Rev-Pb and 35T-Rev-Pb. The prime group, the probe group and the kit are high in detection sensitivity and accuracy of Kras gene mutation, good in specificity and capable of respectively and simultaneously detecting 7 different mutation types.