The present study focuses on Chinese students' mathematics-specific grit and its relationship with students' deep/surface strategies and mathematics achievement. A total of 926 students from secondary schools in China participated in this study. The results of structural equation modeling indicated that consistency of interest had a negative relationship with surface strategies. Perseverance of effort was a positive predictor of both deep and surface strategies. Consistency of interest, perseverance of effort, and deep strategies were positively related to mathematics performance, while students' use of surface strategies had a negative relationship with mathematics achievement. The bootstrap analysis further confirmed the mediating role of learning strategies between grit and mathematics performance. An important finding is that perseverance of effort had double-edged effects on mathematics achievement, with a positive path via deep strategies and a negative path via surface strategies. Consistency of interest positively predicted mathematics performance via a negative relationship with surface strategies. This study provides a possible explanation of these findings from a sociocultural perspective.