This paper proposes a new high-sensitivity, multi-parameter sweat composition analysis sensor utilizing flexible thin film materials. The characteristics of the sensitive materials and high-sensitivity capture mechanism were studied and analyzed. Subsequently, an anti-interference signal acquisition circuit was designed. Finally,a sample sensor was prepared, and a test environment was set up to test its key performance indicators. The results showed that the sweat sensor could realize the real-time monitoring of potassium ion, sodium ion, and glucose, which are components of sweat, with good detection-sensitivity and anti-interference-performance levels. The practicability was much better than that of atraditional detection instrument or single-parameter sweat-sensor detection method.