International innovation cooperation not only helps integrate and allocate national innovation resources, but also helps enhance national international influence. However, international innovation cooperation depends on both domestic factors and bilateral relationships between countries. From a perspective of international trust relationships, this study explores trust relationships between countries ,based on the distinction between ascribed trust and affiliated trust. It explores trust relationships between countries at three aspects: the duration of diplomatic relations, the duration of bilateral investment agreements, and currency exchange agreements. The study analyzes data on innovation cooperation between China and other countries from 2002 to 2020; and it examines the impact of trust relationships between China and other countries on bilateral innovation cooperation,as well as how bilateral institutional distance influences the relationships between countries’mutual trust and bilateral innovation cooperation.Research has found that the level of the trust relationships between countries has a significant positive impact on bilateral innovation cooperation; and institutional distance between the two sides negatively moderates the main effect. The post-hoc analysis indicates a heterogeneity in the moderating effect of institutional distance on the relationships between countries’mutual trust and bilateral innovation cooperation.