In the present experiment, we study the function of methionine on hair follicle development in heat‐stressed Rex Rabbits and its potential molecular mechanism. Rex rabbits were randomly divided into 5 groups (30 replicates per group): control group (20–25°C, fed basic diet), heat stress group (30–34°C, fed basic diet), heat stress + methionine group (30–34°C, fed 0.15% methionine in addition to the basic diet). fed basic diet (control), heat stress + methionine group (30–34°C, fed 0.3% methionine in addition to the basic diet), heat stress + methionine group (30–34°C, fed 0.45% methionine in addition to the basic diet). The results show that heat stress decreases the hair follicle density of Rex rabbits, and the diet methionine addition significantly increases the hair follicle density of heat‐stressed Rabbits (p < .05). Heat stress increased serum HSP70 concentration and skin HSP70 gene expression, 0.15%–0.3% methionine but not 0.45% addition alleviated the effect of heat stress. Dietary 0.15% methionine addition significantly increases the gene expression of Wnt10b, β‐catenin, LEF, FZD4, LRP6, Shh, HGF, EGF, and Noggin in heat‐stressed Rex rabbits and observably decreases the gene expression of BMP2/4 and TGFb. There was no significant effect of methionine on the expression of IGF1 and FGF5/7 gene expression. In conclusion, methionine maybe promotes hair follicle development via TGFβ‐BMP/Shh‐Noggin, Wnt10b/β‐catenin, EGF, and HGF signaling pathways in heat‐stressed rabbits.