The output stability of the laser power has critical influence on la ser interferometer measurement for electron density of plasma.In order to reduc e the number of laboratory staffs to enter the working hall and make up for the shortage of traditional manual control of laser power,this paper proposes an over-all design scheme,which adopts KINGVIE W software as host computer to realize monitoring and recording of power changing remotely and uses programmable logic controller (PLC) as lower machine to achieve the control of laser power.It proves that this system can monitor and record the changing of laser power in real time,improving the level of monitoring in l aser power.Utilizing this method to adjust laser power in long distance,an not only reduce the numbe r of laboratory staffs and improve the efficiency of experiment in the control a ccuracy part,but also adjust the laser power automatically by modifying the parameters of the PLC program and enhance the adaptability of adjustment.This system is running well and can better meet the requirement o f diagnosing electron density of plasma by laser interferometer.