Abstract: In order to switch multiple semiconductor lasers, realize time-sharing work, and reduce the volume of driving circuit, multi-channel selection switch and multi-channel analog switch was used to switch laser diode and photodiode. Different working voltages were set by digital to analog conversion chip. A circuit that can drive multiple different types of laser diodes was achieved. After theoretical analysis and experimental verification, stability test data with long time were obtained. The results indicate that, the output precision of constant current circuit can reach 0.005%, the instability of output power of laser diode with 830nm is 0.048%, and the instability of output power of laser diode with 1550nm is 0.046%. A stable light source is achieved. This result is helpful for the design of small volume drive circuit of multi channel semiconductor lasers.