The invention discloses a safety monitoring system and a monitoring method for a hybrid car, the monitoring system comprises a hybrid control module, an engine management system, a battery management system, a hybrid control unit and a motor control unit. The monitoring method mainly monitors whether the automatic restart of the engine is carried out in conditions of complete cut-off of the power system and whether the engine permissible torque that is transported to an engine control unit by the hybrid control unit is within the effective safety range; as a safety control unit SCU separated from HCU is arranged in the system, the system can use SCU to accept the working state of real time measurement of various gasoline engines, an ISG motor and a high pressure nickel-hydrogen battery through CAN, simulated torque distribution is carried out in SCU, and the distribution result is compared with the distribution situation of HCU. If abnormality is found, a failure mode is started, thus reducing accidents.