In the measurement of miniaturized tunable semiconductor laser spectroscopy(TDLAS),high-precision and high-stability laser driving circuit is one of the key factors which guarantee the measurement accuracy.According to the load capacity,the filter circuit parameters of the linear power supply are analyzed and optimized.The high stable linear power chips of LT3015 and LT1086 are used for power management.Combining with anti-interference routing rules,a linear power with high stability of 1.51×10-3 for 12 hours has been realized.Based on the power supply,the low power consumption Cortex-M3 microcontroller unit(MCU) is used as main controller.The temperature controller WTC3242 and the current controller WLD3343 are managed by the MCU by means of the D/A chip with inner voltage reference.The external current driving signal is connected to current controller by input interface of WLD3343.Finally,different currents driving experiments of laser output are conducted under different temperatures.The experimental results show that measurement errors of laser output for short-time and long-time are 0.01 wave number and 0.014 wave number,respectively.Meanwhile,linear correlation coefficient of driving current and light intensity is more than 0.9958;standard deviation is less than 7.60843×10-4;Allan variance is less than 2.597×10-4 at 5 seconds.