The experiment designed four kinds of soil compaction treatment ［soil bulk density of 1.2 (CK₁), 1.3, 1.4, 1.5 g·cm^-3］, and four inoculation treatments ［Fm, Ri, Fm+Ri, and noninoculation (CK₂)］ with inoculating two kinds of arbuscular mycorrhizal fungi (including Funneliformis mosseae，F_m and Rhizophagus intraradices,Ri) before compaction treatment, and a total of 16 treatments. We analyzed the effects of different treatments on the physiological and ecological indexes of Festuca elata variety ‘Ai Rui 3’, and provided a theoretical basis for the application of AMF in compacted soil. The results showed that: (1) the mycorrhizal infection rate and mycelial density of the roots of tall fescue decreased gradually with the increase of soil bulk density. Compared with CK₁, the infection rate of roots of high fescue roots inoculated with Fm, Ri and Fm+Ri under treatment with soil bulk density of 1.5 g·cm^-3 was significantly reduced by 27.8%, 39.8% and 30.0%, respectively. The mycelial density decreased significantly by 43.8%, 42.1% and 43.8%, respectively. Moreover, under 1.5 g·cm^-3 soil bulk density, the mycorrhizal infection rate and mycelial density of Fm+Ri treatment increased by 17.3% and 25.2%, respectively, which was 53.0% and 36.3% higher than that of single inoculation, respectively. (2) Inoculation with AMF can effectively increase the plant height, tiller number and dry matter quality of tall fescue plants under soil compaction stress, and significantly improve the tolerance of tall fescue. Plant height, tiller number and dry matter quality of Fm+Ri treatment were significantly increased by 36.1%, 39.5% and 144.0%, respectively, under 1.5 g·cm^-3 soil bulk density compared with CK₂. (3) Inoculation with AMF significantly increased the root activity and catalase (CAT) activity of tall fescue under soil compaction stress. The root vigor and CAT activity of Fm+Ri inoculated with 1.4 g·cm^-3 soil bulk density were 1.4 times and 1.5 times than that of CK₂, respectively. (4) Inoculation with AMF can significantly increase the contents of chlorophyll a, b and total chlorophyll in tall fescue under soil compaction stress. Inoculation with Fm+Ri treatment in the soil bulk density of 1.5 g·cm^-3 was 43.1%, 100.0% and 59.3% higher than that of the CK₂. (5) Inoculation with AMF significantly increased the net photosynthetic rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s) of tall fescue under soil compaction stress, and significantly decreased the intercellular CO₂ concentration (C_i) of leaves. Inoculation with Fm+Ri treatment was 52.5%, 33.3%, 181.1% and -32.9% higher than that of the CK₂ under the soil bulk density of 1.5 g·cm^-3. In summary, soil compaction stress significantly inhibited the infection of AMF, and coinoculation significantly promoted the infection of AMF on roots, and the effect of coinoculation with Fm+Ri was significantly better than single inoculation. AMF can enhance its own resistance to soil compaction by enhancing the activity of tall fescue roots, reducing the damage caused by oxidative stress, increasing plant chlorophyll content and photosynthesis.