In response to the poor water flooding effect，high water cut（≥75%），low recovery rate（14.7%），in the Chang 6 tight oil reservoir of the Yanchang oilfield，which is characterized by high salinity formation water（≥120 000 mg/L），high calcium and magnesium（Ca²⁺ content≥20 000 mg/L，Mg²⁺ content≥400 mg/L），and strong heterogeneity（permeability contrast =50），and the current foam systems' inability to adapt to these conditions，eight Gemini surfactants were evaluated for their foaming performance， half-life，and comprehensive foam index under simulated reservoir conditions using a high-temperature and high-pressure foam instrument and a tight reservoir imbibition system. The best foaming agent，auxiliary agent，and their concentrations were optimized to construct a low interfacial tension，calcium and magnesium resistant，and oxygen-reduced air foam system. The effects of different temperatures，Ca²⁺ and Mg²⁺ contents，oil saturation，and pH values on the foaming volume and half-life of the system were evaluated，and the oil displacement efficiency and imbibition efficiency of the system in heterogeneous reservoirs were investigated. The results showed that 0.4% LY-12（dodecyldodecyl hydroxysulfonate）+ 0.1% LX-14（tetradecyl amino acid salt） was the best foam system. Temperature，Ca2 + content，oil content，and pH had a significant impact on the foaming volume and foam half-life，while the effect of Mg2 + content was relatively small. The best foam performance could be guaranteed under conditions of temperature ≤45 ℃，Ca²⁺ content ≤20 000 mg/L，oil content ≤ 30%，and neutral pH，with a comprehensive foam index ≥12 000 mL min and an interfacial tension of 6.63×10^-2 mN/m. When the permeability contrast was 50，the continuous foam flooding in heterogeneous reservoirs had a 7% higher comprehensive oil displacement efficiency than the foam slug followed by water flooding. When the permeability was 0.96×10^-3 μm²，the imbibition efficiency reached up to 42.88%，demonstrating good adaptability to low-permeability reservoirs.