The invention relates to a controller of a high-voltage chain type static and synchronous compensator, belonging to the technical field of electric automation equipment and comprising a main controller and three-phase split-phase controllers, wherein the main controller is used for realizing functions, i.e. data collection and processing, closed loop control, monitoring communication and the communication of the split-phase controllers; and each split-phase controller is used for realizing functions, i.e. communication with the main controller, the PWM pulse generation of a three-phase current conversion chain and the PWM pulse signal distribution of the three-phase current conversion chain. The controller can realize the high isolation and insulation voltage strength between the controller and a main circuit with full digitalization, can realize the high-speed communication by being linked with the main circuit, has high-speed computation capability to realize a fast computation and control function, has a multiple-pulse generation and distribution function, can realize the multivoltage/current analog quantity input and the multi-way switch value input and output and can be used for the chain type static and synchronous compensator (STATCOM) realizing output voltage of more than 10 kV.