This paper, grounded on the Dual-Process Model, investigates the impact of the translator’s mental reality, processing paradigms and translation strategies of multi-word chunks on the English translation of Chinese featured multi-word chunks in political texts with a longitudinal empirical approach. The research findings show that 1) six-word chunk translations appear to be the most difficult for low- to medium-leveled learner translators and three- word chunk translations rank the second; 2) four-word chunk translations see higher quality but the between-group difference proves bigger; 3) the processing paradigms in translating chunks of varied sizes manifest themselves as a continuum model, developing from analytic approach to holistic one as translators of bilingual proficiency and translation competence progresses from low to high levels; 4 ) application of translation strategies varies between learner translators and professional translators as the former prefers foreignization, and word-for-word translation while the latter stay consistently loyal to homestigation and free translation. The results indicate that there is an urgent need for Chinese learner translators to improve the interconnection between chunk representations of two languages, and to consciously control and appropriately balance their processing paradigms and strategies in the Chinese-English translation of multi-word chunks.