Abstract: Current-carrying capacity of a cable is generally determined by the core temperature, which is influenced by the surrounding medium and environmental parameters. Therefore, accurate environmental parameters are the prerequisite for the accurate calculation of real-time cable current-carrying capacity. Aiming at the difficulty of accurately obtaining real-time environmental parameters for actual submarine cable operation, a mathematical model and solution method for the inversion of environmental parameters were proposed. Firstly, a mathematical model for the inversion of environmental parameters of submarine cables was constructed, and based on the improved sparrow search algorithm, an effective solution method for the above inversion model was proposed. Then, in order to improve the performance, a strategy to improve sparrow search algorithm by combining with salp swarm algorithm was proposed, and the Lévy flight method was introduced into sparrow individual position update rule, which could enhance algorithm's ability to search for the optimal point and to jump out of the local optimal point. At the same time, a suitable convergence factor was given. Results of an example showed that the inversion model and algorithm could obtain accurate thermal conductivity of sea soil, and the improved sparrow search algorithm could enhance the accuracy and efficiency.