The present invention discloses a real-time kernel of open CNC systems and a real-time control method of tool-paths. The real-time kernel translates a real-time control of the tool-paths into sending synchronous pulses into the servo drivers in accordance with the control rhythms Δti (i=1, . . . , n) in the follow-table and achieves the openness of real-time control method and real-time control process. The real-time kernel has the most simple and reliable multi-axis synchronization capability with high-speed and high-precision, and leads to major changes in the field of digital control method. The real-time kernel no need to configure a real-time operating system and a fieldbus, its core function is only to write the control rhythm into the T-division timer, and to send linkage commands into the servo drivers designated by the state-word, therefore its function and architecture are extremely simple and high reliability.