A voltage control method and apparatus of a central bus in a power system are provided. The method comprises: S1: obtaining a predetermined voltage and a current voltage; S2: obtaining a first voltage adjustment of the generator and a second voltage adjustment of the dynamic reactive power compensation device; S3: sending the first voltage adjustment and the second voltage adjustment; S4: judging whether a current reactive power of the dynamic reactive power compensation device is between a first predetermined reactive power and a second predetermined reactive power; S5: if yes, obtaining a third voltage adjustment of the generator and a fourth voltage adjustment of the dynamic reactive power compensation device; S6: sending the third voltage adjustment and the fourth voltage adjustment; repeating steps S1-S7 after a predetermined period of time; S7: if no, repeating steps S1-S7 after the predetermined period of time.