According to the Power-Voltage-Intensity of current(PVI) characteristic of high power infrared laser diode,one constant-current power scheme with two control loops is proposed.The hardware-based control loop performs high-precision current regulation; the software-based digital control loop is used to adjust the DCDC module output voltage according to the laser′s working current,and thus maintains the steady-state voltage drop of MOSFET in constant-current circuit almost constant.This type of structure effectively reduces the power consumption,and meanwhile holds high current accuracy.Firstly,the PVI characteristic is analyzed and the system structure is proposed.Then the design principle of the constant-current driver circuit and high-efficiency DCDC power supply circuit with adjustable output voltage are designed.The implement of communication protocol and the control algorithm of DCDC output voltage are discussed in detail.Finally,DCDC efficiency and laser current control effect are given,and the comparison test result further reveals the efficiency advantage of the proposed design scheme.