Abstract: [Purpose/Significance] This paper, from the perspective of information user-centered, aims to clarify the user cognitive characteristics, emotional aggregation process, and the triggering mechanism of cognitive-affective unit on user participation behaviors within agricultural product promotion short videos. [Design/Methodology] This paper selects 5,357 online comments from 347 short videos on the "Dongfang Zhenxuan's Own Products" account on the TikTok platform, and conducts a three-level coding using Grounded Theory. It combines the Cognitive-Affective Personality System Theory（CAPS）to construct a user cognitive characteristic and participation behavior model, extracts key elements and weights, and uses the Greedy Algorithm to identify the "cognitive-affective-behavior" representative path. [Findings/Conclusion] Four user cognitive characteristics are identified: product cognition, content cognition, brand cognition, and streamer cognition. Surface-level and deep-level emotions converge through three mechanisms, activating cognitive-affective units. User participation behavior are divided into community interaction and consumption interaction, with four typical cognitive-affective units identified. [Originality/Value] This study introduces CAPS into the context of agricultural product promotion short videos, extending its explanatory boundary in the information user behavior domain, and provides a theoretical basis for short video content creation and agricultural assistance practices in agricultural product e-commerce.

Keywords: Short video for agricultural product promotion, User participation behavior, User cognitive characteristics, Agricultural product e-commerce, Cognitive-Affective Personality System（CAPS）