Middle school serves as a pivotal juncture in career development, where adolescents grapple with adaptability challenges during transitional phases such as entrance exams and the selection of elective majors. Simultaneously, they embark on integrating their ongoing learning tasks with their ideal aspirations to lay the groundwork for future career development. Against this backdrop, the significance of career exploration and understanding future developmental directions becomes particularly pronounced. To investigate the intricate relationship between career exploration and the clarity of one’s future work-self, along with the moderating role of proactive personality, this study employed the career exploration scale, proactive personality scale, and clarity of future work-self scale. Data from 457 high school students were collected, revealing a substantial positive correlation between career exploration and both future work self-clarity and proactive personality. Adjusting for gender and age highlighted proactive personality as a regulatory factor influencing the relationship between career exploration and future work self-clarity. Furthermore, the results underscored the crucial moderating role of proactive personality in shaping the connection between career exploration and the clarity of future work-self. In-depth analysis revealed noteworthy interactions, particularly with the environmental exploration dimension (standard coefficient of 0.849, p < 0.001). Similarly, interactions with self-exploration, goal-system exploration, and information quantity dimensions were also significant, featuring standard coefficients of 0.905 (p = 0.002), 0.935 (p < 0.001), and 0.854 (p < 0.001), respectively. In essence, these findings illuminate the nuanced dynamics at play, emphasizing the amplified connection between career exploration and the clarity of future work-self in the presence of higher proactive personality levels. This insight holds implications for educators, counselors, and researchers invested in fostering comprehensive career development strategies for adolescents.