The construction of Songxin Fishway is one of the important engineering measures to restore the connectivity of Heishui River, an alternative tributary of fish habitat in Baihetan Reservoir area of Jinsha River. In this study, the Songxin Fishway in the Heishui River, monitoring and evaluation of fish passage effect in Songxin Fishway were studied by net catch method and radio frequency identification (RFID) remote sensing technology. The results showed that:(1) A total of 19 species of fish were detected in the downstream of the Songxin dam site of the Heishui River, of which 12 species could reach the upstream river smoothly through the fishway. (2) The fish diversity was influenced by the motivation of fish migration in a seasonal pattern, with the Shannon-Wiener index of fish diversity at the inlet and exit of fish passage being significantly lower in the non-migratory period (December) than in the migratory period (March and May); (3) The import attraction rate of Schizothorax wangchiachii is 31.50% and the passage rate is 44.44%. Using the monitoring data of net, it was found that:when the water temperature exceeded 20℃, the species and quantity of fish decreased with the increase of water temperature; When the discharge in the fishway exceeded 0.50 m³/s, the species and quantity of fish decreased with the increase of discharge in fish passage. In order to identify the key factors affecting the fish passage effect, the S. wangchiachii as a study subject, a Cox proportional hazard regression model was constructed based on multiple factors (fish passage flow, water temperature, circadian rhythm, pH, wet weight, body length etc.). It was found that:fish passage discharge, water temperature and circadian rhythm were the key factors affecting the fish passage effect; When water temperature varied from 14.0 to 20.0℃, the passing rate of S. wangchiachii increased with water temperature. When the discharge in the fishway ranged from 0.01 to 0.50 m³/s, the passing rate of S. wangchiachii showed an increasing trend with the increase of the discharge in the fish channel. The circadian rhythm had a significant effect on the abduction of S. wangchiachii, and S. wangchiachii preferred night upstream migration. The research results are helpful to the fish habitat restoration and the protection of fish resources in Heishui River, and provide a theoretical basis for the construction of fishway in cascade hydropower stations of Heishui River and low head sluice dams of mountainous rivers in southwest China.