The invention discloses a kit for detecting B-raf gene V600E mutation, and a detection method thereof. The kit comprises B-raf gene V600E mutation detection mixed liquid, wherein the B-raf gene V600Emutation detection mixed liquid comprises a B-raf gene V600E mutation detection specific primer pair, a B-raf gene specific probe, a competitive inhibition nucleotide sequence, thermostability DNA (deoxyribonucleic acid) polymerase, thermostability restriction enzyme, reaction buffer solution and reaction enhancer. The kit has the beneficial effects that an ARMS-PCR (Amplification Refractory Mutation System-Polymerase Chain Reaction) fluorescence probe technology, a competitive inhibition Blocker technology, an oligonucleotide modification technology and a TspRI restriction enzyme technology are subjected to combined adaptation, mutation samples and wild samples can be more favorably distinguished so as to realize detection sensitivity and specificity better than similar technologies or products, B-raf gene V600E site mutation can be quickly, conveniently, sensitively and economically detected, and the kit is suitable for popularization application and industrialization.