The invention discloses a design method for primers and a probe for amplifying a low-concentration mutation target sequence. The design method includes the steps that the mutation position (a mutational site, namely a 0 site) of a target sequence to be amplified is determined; a 15-25 bp nucleic acid fragment including the 0 site base is selected in the negative direction of the mutational site to serve as the forward primer, and a 12-25 bp nucleic acid sequence is selected from the 1 site base or the 0 site base in the positive direction of the mutational site to serve as a probe sequence of an amplification system; the reverse primer is designed at the suitable position of the 3'direction downstream of the probe sequence according to a conventional method. According to the design method for the primers and the probe, the target fragment can be effectively (with high specificity and efficiency) amplified under the background of a high-content wild type template particularly for point mutation, deletion mutation and insertion mutation in gene mutation, a fluorescence real-time PCR technology is combined, and the problem that at present, sensitivity is poor in clinic tumor detection and drug susceptibility detection can be solved effectively.