The Pioneer anomaly, discovered in the deep‑space exploration missions of Pioneer 10/11, refers to the phenomenon that the measured acceleration of the spacecraft is persistently higher than the predictions of traditional gravitational theories during its departure from the Sun, with the anomalous deviation stably maintained at approximately (8.74±1.33×10-10m/s²). This phenomenon deviates significantly from the expectations of traditional gravitational theories. Mainstream explanations such as thermal radiation and systematic errors cannot fully account for the distance‑dependent and long‑term stable characteristics of the anomaly. Based on observational facts without constructing complex models, this paper proposes an extremely simple conjecture: the anomaly may originate from the long‑range attenuation effect of a spatial topological field not incorporated into the traditional gravitational framework. By analyzing decades of exploration data, this study verifies the persistence and stability of the anomaly, and puts forward verifiable observational schemes for the conjecture, such as deploying spacecraft on deeper space orbits for higher‑precision acceleration measurements. This conjecture provides a new research perspective for unraveling the physical essence of the Pioneer anomaly and offers observational evidence for delimiting the applicable scope of extended gravitational theories.