The mTOR signaling pathway has been demonstrated to be related to the development of osteoarthritis (OA) by regulating expression of autophagy regulators. Few studies have shed light on the association of mTOR-pathway-related gene variants with OA risk. Totally 441 OA patients and 533 controls were recruited and their genotypes for mTOR-pathway-related gene variants were determined based on the matrix-assisted laser desorption/ionization time of flight mass spectrometry. Genetic risk scores (GRS) were calculated to evaluate the combined effect of these polymorphisms on OA risk. No significant differences were observed in genotypic and allelic frequencies of AKT rs1130233/REDD1 rs1053639 polymorphisms. However, the mTOR rs1034528 polymorphism was demonstrated to be related to an increased risk of OA, especially among smokers and individuals aged ≥60 years. This single nucleotide polymorphism (SNP) also showed significantly correlation with the Lequesne's index. Similarly, the IRS1 rs1801278 polymorphism increased the risk of OA among smokers, drinkers and individuals aged ≥60 years. A strong positive correlation was found between PTEN rs3830675 polymorphism and OA risk, and this SNP was more frequent in the smokers and drinkers groups. No association was found between IRS1 rs1801278/PTEN rs3830675 polymorphism and OA characteristics. Additionally, there was a strong interaction between genetic factors and lifestyles under the combined models (IRS1 rs1801278/ PTEN rs3830675 polymorphism and smoking/drinking). A high GRS was positively related to an increased risk of OA. In summary, three gene polymorphisms (mTOR [rs1034528], IRS1 [rs1801278] and PTEN [rs3830675]) were found to affect the risk of OA development by regulating the mTOR pathway.