Abstract: Habitat assessment is a prerequisite for in-situ conservation of fish, and appropriate model algorithms is an important basis for improving the prediction accuracy of habitat assessment models. This study aims to identify the optimal algorithm for the habitat suitability index (HSI) model of Glyptothorax sinensis and to scientifically evaluate its suitable habitat distribution. We utilized fishery catch data and 13 environmental factors collected synchronously from the Heishui River from 2018 to 2019. A one-dimensional nonlinear function was employed to fit a single environmental factor curve, and HSI values of G. sinensis were calculated using the maximum value method, minimum value method, arithmetic mean model, geometric mean model, and weighted moving average. The results indicate that among the various model algorithms, the arithmetic mean model and weighted moving average model exhibited the smallest prediction error, while the maximum and minimum value method showed significant prediction error and deviated notably from the actual distribution of G. sinensis. Therefore, caution should be taken when choosing model algorithms. Overall, the HSI index of G. sinensis in the Heishui River shows an upward trend from the upstream to the downstream, with sections S3 and S4 exhibiting HSI values greater than 0.7. Water temperature and elevation are the main driving factors for the spatial distribution differences in G. sinensis habitat. The arithmetic mean model and weighted moving average model are identified as the optimal algorithm for predicting the habitat suitability index of G. sinensis in the Heishui River. The research results can provide reference for the assessment of fish habitats in the Heishui River and promote the protection of fish habitats.