The invention discloses a polyacrylamide gel electrophoresis method for detecting the mutation polymorphism of 5 basic groups in gene coding region of a goat growth hormone (GH). The method comprises the following steps of: performing amplification under a PCR condition by using two pairs of reaction (PCR) primers P1 and P2 in the presence of a goat genome DNA sequence as a template, TaqDNA polymerase, Buffer (a buffer environment), Mg2<+> and dNTPs; determining the sizes of amplification objective fragments according to an agarose gel electrophoresis; screening the mutation of the 5 basic groups in the gene coding region of the goat GH by using a DNA sequencing technique, and then performing genotyping and gene frequency analysis on the SNPs of a GH gene; and performing association analyses on the growth traits of a Boer goat and three-moon's age filial generations (F1 and F2) of the Boer goat and a Guanzhong dairy goat, wherein the results of the show that the detected SNPs sites of the P1 and the P2 of a GH gene can be used as molecular markers of the early selection (three-moon's age) of the growth traits of a goat.