To investigate the protective effect of yak blood oligopeptides on hypoxic injury of H9c2 cardiomyocytes and its mechanism. The hypoxia injury model was established by culturing H9c2 cardiomyocytes in vitro, randomly divided into 5 groups (n=6): normal control group, hypoxia group, low-dose yak blood oligopeptide group, middle-dose yak blood oligopeptide group and high-dose yak blood oligopeptide group. The results showed that: the cell survival rate of hypoxia group was significantly lower than that of control group (P＜0.01), the rate of apoptosis was significantly increased (P＜0.01), the release level of LDH was significantly increased (P＜0.01), mitochondrial membrane potential decreased significantly (P＜0.01), which showed that hypoxia could cause damage to H9c2 cardiomyocytes. At the same time, compared with the anoxic group, yak blood oligopeptides could inhibit mitochondrial membrane potential decline, improved the T-AOC level of cells, reduced the level of TNF-α, inhibited the release of cytochrome C, upregulated the expression of anti-apoptotic proteins (Survivin, p-Akt, Akt), decreased the activity of apoptosis protein (Caspase-3/9), and affected the level of mRNA encoding of the above protein. The above results showed that the protective effect of yak blood oligopeptides on H9c2 cardiomyocytes was closely related to the inhibition of PI3K-Akt signal transduction pathway and the protection of mitochondrial structural and functional integrity.