“The Three-Body Problem”, English version of the Chinese novel “Santi”, is the first translated novel to have received “Hugo Award for Best Novel”, the world’s best laurel for science fiction. This paper studies how the translator Ken Liu’s subjectivity contributed to the success of the translation from the perspective of Eco-translatology. The study focuses on how Ken Liu adapted himself to the translational eco-environment and what translation strategies and skills he selected in the linguistic, cultural, and communicative dimensions. Moreover, the quality of the translation is evaluated with the criteria proposed in Eco-translatology. With the help of Python, a quantitative and qualitative analysis of readers’ comments on “The Three-Body Problem” is conducted. The research finds that (1) In the adaptation stage, Ken Liu was not passively constrained by the translational eco-environment. His subjectivity based on his bilingual and bicultural competence satisfied both his own internal requirements and the external requirements of the translational eco-environment; (2) In the selection stage, Ken Liu creatively succeeded in achieving the correspondence between the source text and target text in the linguistic, cultural and communicative dimensions; (3) The English version of “Santi” has survived in the western translational eco-environment by way of a high degree of holistic adaptation and selection.