Abstract: A driving system for the pump source of the ultrashort pulse laser was developed, which could provide high precision, high stability and high flexibility of constant-temperature control and constant-current drive for the five semiconductor lasers simultaneously. In order to improve the flexibility and integration of the driving system, the hardware part adopted the modular design scheme that the host computer, control board, driving board and power supply module were separated. The driving system program was developed based on embedded real-time operating system μC/OS-III, which improved the real-time performance and expansibility of the system program. In the output correction part of the system, incremental PID algorithm optimized by genetic algorithm was adopted, the overshoot and the time to establish dynamic equilibrium of the system were reduced. The driving system had complete protection measures, such as soft-start and soft-shutdown, driving loop monitoring, overtemperature protection and other functions, to ensure the stable operation of the pump source. In practical application, the temperature stability of the semiconductor laser is better than 0.035%, and the output current stability of the driving system is better than 0.001%. The developed driving system is integrated into a 1.5 μm femtosecond fiber laser, the driving system drives five semiconductor lasers as the pump source, the emission spectrum, output pulse trains and single pulse profile of the seed laser and the laser amplifier are stable, The output power stability of the 1.5 μm femtosecond fiber laser is 0.16% after three hours of continuous testing.