Based on the Grey Relation Analysis (GRA), this study establishes an evaluation model of motivational factors influencing English learning achievement. Through a questionnaire survey among 266 first-year academic engineering graduate students, this study clarifies the impacts of achievement goal setting and self-efficacy (SE) on English learning achievement (ELA). The results show that: 1) Mastery approach goal, achievement approach goal, English learning behavior self-efficacy, English learning plan self-efficacy and English learning strategy self-efficacy have direct positive influences on English learning achievement, while mastery avoidance goal and performance avoidance goal have direct negative influences on English learning achievement; 2) Mastery approach goal has the biggest impact on self-efficacy, followed by achievement approach goal, English learning plan self-efficacy, English learning strategy self-efficacy, mastery avoidance goal, performance avoidance goal, and performance avoidance goal; 3) On the whole, English learning achievement is related more to achievement goal setting than self-efficacy. This study also demonstrates that compared with traditional evaluation methods of motivational factors, Grey Relation Analysis is superior for its objectivity. The results of the present study can give some hints on English teaching.