This study presents a novel polyimide (PI) with low dielectric loss, featuring a linear backbone structure with ester groups and ether bonds. The material exhibits low dissipation factor (Df) values of 0.0015–0.0024 at 10 GHz, even under high humidity and temperature conditions. The low Df is attributed to high orientation and crystallinity, which restrict molecular motion and reduce dielectric loss. The material also demonstrates excellent moisture resistance, with low water absorption rates, ensuring stable dielectric properties in humid environments. The study highlights the importance of combining ester groups and ether bonds in PI structures to achieve low dielectric loss and high thermal stability. The material's performance is further enhanced by its high orientation and crystallinity, which improve mechanical strength and electrical breakdown strength. The research provides a design strategy for achieving inherently low-dielectric-loss polyimides, with potential applications in high-frequency communication devices and microelectronics. The findings demonstrate that the combination of ester groups and ether bonds in PI structures can significantly reduce dielectric loss while maintaining good thermal and mechanical properties. The study also shows that the material's dielectric properties are stable across a wide temperature range, making it suitable for various high-frequency applications. The research contributes to the development of advanced dielectric materials for next-generation communication technologies.This study presents a novel polyimide (PI) with low dielectric loss, featuring a linear backbone structure with ester groups and ether bonds. The material exhibits low dissipation factor (Df) values of 0.0015–0.0024 at 10 GHz, even under high humidity and temperature conditions. The low Df is attributed to high orientation and crystallinity, which restrict molecular motion and reduce dielectric loss. The material also demonstrates excellent moisture resistance, with low water absorption rates, ensuring stable dielectric properties in humid environments. The study highlights the importance of combining ester groups and ether bonds in PI structures to achieve low dielectric loss and high thermal stability. The material's performance is further enhanced by its high orientation and crystallinity, which improve mechanical strength and electrical breakdown strength. The research provides a design strategy for achieving inherently low-dielectric-loss polyimides, with potential applications in high-frequency communication devices and microelectronics. The findings demonstrate that the combination of ester groups and ether bonds in PI structures can significantly reduce dielectric loss while maintaining good thermal and mechanical properties. The study also shows that the material's dielectric properties are stable across a wide temperature range, making it suitable for various high-frequency applications. The research contributes to the development of advanced dielectric materials for next-generation communication technologies.