Orbital period and multi-color light curves′ investigation of OW Leo are presented for the first time. The orbital period of OW Leo is corrected from P = 0.325545 days to P = 0.32554052 days in our work, and the observational data from the All-Sky Automated Survey for SuperNovae (ASAS-SN) are used to test the newly determined orbital period. Then, the phased light curves are calculated with the new period and the Wilson-Devinney program is applied to model the light curves, which reveal that OW Leo is a W-subtype shallow contact binary system (q = 3.05, f = 12.8 %). The absolute physical parameters of the two component stars are estimated to be M ₁ = 0.31(1)M _⊙, M ₂ = 0.95(3)M _⊙, R ₁ = 0.63(1)R _⊙, R ₂ = 1.04(1)R _⊙, L ₁ = 0.43(1)L _⊙ and L ₂ = 1.01(2)L _⊙. The evolutionary status shows that the more massive star is less evolved than the less massive star. OW Leo has very low metal abundance, which means its formation and evolution are hardly influenced by any additional component. It is formed from an initially detached binary system through nuclear evolution and angular momentum loss via magnetic braking, and has passed a very long time of main sequence evolution.

首次提出OW Leo的轨道周期和多色光变曲线研究。OW狮子座的轨道周期是从修正P =0.325545天到P =0.32554052天在我们的工作，并从全天空自动测量超新星（ASAS-SN）的观测数据被用于测试新确定的轨道周期。然后，用新周期计算相位光变曲线，并应用Wilson-Devinney程序对光变曲线进行建模，表明OW Leo是一个W亚型浅接触二元系统（q = 3.05，f = 12.8 %） . 双组分分的绝对物理参数估计是中号 ₁ = 0.31（1）中号 _⊙, M ₂ = 0.95(3) M _⊙ , R ₁ = 0.63(1) R _⊙ , R ₂ = 1.04(1) R _⊙ , L ₁ = 0.43(1) L _⊙和L ₂ = 1.01(2) L _⊙. 演化状态表明，质量较大的恒星比质量较小的恒星演化得少。OW Leo 的金属丰度非常低，这意味着它的形成和演化几乎不受任何额外成分的影响。它是由最初分离的双星系统通过核演化和磁制动角动量损失形成的，经历了很长时间的主序演化。