The present invention provides a system for failure safety control between controllers connected to an HCU via CAN communication. The system includes an ECU, an MCU, a TCU, a BMS and an HCU. The ECU is connected to the HCU via CAN communication, and configured to output a ready signal to the HCU and control operation of an engine. The MCU is connected to the HCU via CAN communication, and configured to output a ready signal to the HCU and control operation of a motor. The TCU is connected to the HCU, and configured to output a ready signal to the HCU and control operation of a transmission. The BMS is connected to the HCU via CAN communication, and configured to output a ready signal to the HCU and manage a state of a battery. The HCU is configured to output ready signals to the ECU, the MCU, the TCU and the BMS to control operation of the controllers, control a hybrid operation mode, and have CAN communication line signal detection terminals for detecting states of CAN communication connections to the controllers and ready signal detection terminals for detecting ready signals input from the respective controllers.