The invention discloses primers and probes and a kit for detecting five mutation types of a human PIK3CA gene. According to each group of the five groups (PIM1-PIM5) of the primers and probes, the mutation primer can be combined with a conserved sequence of the PIK3CA gene, a mutation ARMS primer can be specially combined with a corresponding mutation sequence of the mutation ARMS primer to amplify the mutation sequence, the detection probe can be combined with an amplified fragment, and the blocking probe can be specially combined with a wild type sequence corresponding to a mutation locus to inhibit wild type nonspecific amplification. Accordingly, by adopting a specific mutation primer and probe blocking technology, the five mutation types of the PIK3CA gene can be accurately detected; through the established kit of a real-time fluorescence PCR amplification reaction system, rapid detection on the PIK3CA gene mutation is facilitated, operation is easy, and a result is easy to read; the detection method is high in sensitivity, and 50-copy mutation can be stably detected; the specificity is good, no nonspecific amplification is generated in 20-ng wild type genome DNA, and the detectability reaches up to 1%.