Through the bending loading test of hybrid fiber lithium slag concrete beam after salt freezing cycle, the mechanism of salt freezing damage of hybrid fiber lithium slag concrete beam was analyzed and its bending performance in salt freezing environment was investigated. Based on the calculation method of bending bearing capacity of ordinary reinforced concrete bending members in the current specification, the formula of fiber influence coefficient and salt damage coefficient with dynamic elastic modulus as parameter were used to modify the formulas in the specification, and the formula for calculating the bending bearing capacity of hybrid fiber lithium slag concrete beams under salt freezing was obtained. The calculated comparison results show that the results obtained by using the modified formula were closer to the experimental values than those calculated by the specification. Modified formula can be used for the analysis and design of the bending members of the hybrid fiber lithium slag concrete under the salt freezing environment.