In order to study the influence of structural parameters and flow conditions of surge tanks on the local head loss coefficient, a multivariate linear regression model was established based on the measured data of physical models. The regression equations for calculating the head loss coefficient of the tailrace surge tank with a connecting pipe were obtained, then the results of the equations were compared and analyzed with those of the hydraulic model test. The research shows that the regression analysis results are in good agreement with those of the hydraulic model test, and the corresponding regression equations can well reflect the changeable rule of local head loss coefficient under the interaction of diversion ratio, pipe diameter ratio and flow pattern. So these equations have strong engineering applicability and can be applied to the calculation of head loss coefficient in the hydraulic design of surge tanks.