The invention relates to the technical field of gene polymorphism detection, in particular to a detection method of yak FOXO1 gene single nucleotide polymorphism and a kit thereof. The detection method comprises the following steps: 1) preparing a yak FOXO1 gene amplification product; 2) synthesizing a high and low temperature interior label; 3) preparing an HRM-PCR (High Resolution Melt-Polymerase Chain Reaction) amplification product; 4) collecting a fluorescence signal. Compared with an HRM method used for detecting polymorphic sites in the prior art, a gene probe designed by the detection method is more accurate and flexible in positioning, is accurate in parting, does not need PCR post-processing, has high working efficiency and good repeatability and is low in sample quality and quantity requirements, especially, the concentration requirement of a DNA template can be lowered to 0.1ng/mu L, and time and labor are saved when a sample size is large. Meanwhile, the detection kit has the advantages of high sensitiveness, high detection speed and good stability.