Aiming at the key issues of speed cooperative control of dual permanent magnet synchronous motors for transmission line robots, an improved control strategy is proposed. Firstly, in terms of rotational speed loop control, a non-singular terminal sliding mode controller based on the new approach law was designed, and combined with the expanded state observer to conduct real-time observation and compensation of uncertain disturbances in the system, thereby improving the speed tracking performance of the motor. Secondly, in terms of synchronous control, a cross-coupling control architecture was adopted, and a fuzzy control error compensator based on the improved particle swarm optimization （PSO） algorithm was designed. The fuzzy control parameters were tuned through the optimization algorithm, thereby reducing the synchronous error of the dual-motor rotational speed under external disturbances. The simulation experiment results show that the proposed control strategy exhibits significant advantages in terms of robustness, rotational speed tracking accuracy and synchronization performance, providing an effective solution for the high-precision control of live-line operation robots.