The electron cyclotron heating system including four gyrotrons is being developed in the Institute of Plasma Physics, Chinese Academy of Sciences. The filament is an important part of the gyrotron, which is used to heat the cathode. The gyrotron output power can be controlled by adjusting the filament power. We have developed the filament power control and measurement system using Labview. The filament characteristics were tested using this power control system. The test results show that the filament current can be fitted with the e-exponential function of the filament voltage. It can be seen that as the voltage increases, the filament resistance gradually increases. We have developed a new "burst" function to prevent the beam current from dropping too fast, which is conducive to long pulse stable operation of the gyrotrons.