The invention discloses a high-voltage pulse generator and a communication method thereof. The high-voltage pulse generator comprises a main controller and sub-controllers, wherein data transmitted between the main controller and the sub-controllers at least comprise a first type of data and a second type of data; and the second type of data comprises at least two kinds. The communication method comprises the following steps: when the first type data is transmitted at present, transmitting a part of the second type of data; when transmitting the first type of data next time, transmitting the other part of the second type of data; and repeating the previous steps till the transmission of the second type of data is finished. Through adoption of the high-voltage pulse generator, high transmission real-time performance of the first type of data is ensured. Moreover, less controller pin resources are occupied; the cost is relatively low; and the problem of data conflict is solved.