The invention provides a design method of amplification primers. The design method is characterized in that the amplification primers adopting hairpin structures are designed and single-stranded DNA fragments are formed at the two ends of an amplification product. The invention provides two gold nanoparticle probes; DNA sequences modified by the probes are complementary to the single-stranded DNAfragments at the two ends of a PCR product of DNA to be detected. The invention provides a quantitative PCR detection method based on gold nanoparticles. The quantitative PCR detection method comprises the following steps: (1), selecting a DNA sequence to be detected, and designing a pair of specially-structured amplification primers, wherein the pair of specially-structured amplification primersare designed to be the hairpin structures; (2), performing a PCR reaction in a system containing a DNA template to be detected, the pair of specially-structured amplification primers, Taq DNA polymerase and dNTP to obtain the PCR product; (3), preparing DNA-modified gold nanoparticle probes; (4), adding the probes into the PCR product, and hybridizing with the PCR product; (5), measuring the change of the absorbance or a dynamic light scattering signal of the gold nanoparticles. With the quantitative PCR detection method, the operation is simple, the PCR product can be rapidly detected, and the sensitivity is high.