The invention discloses a coke oven gas refining process security system. An electric tar precipitator is connected with a fan boosting unit, an outlet pipe A of the fan boosting unit is connected with a desulfurization and naphthalene removal unit, the desulfurization and naphthalene removal unit is provided with an outlet pipe E, the outlet pipe A bypasses the outlet pipe E through a communication pipe B, and the communication pipe B is provided with a gas-closed valve C. The system can not only be automatically started when airflow blockage of a coke oven gas refining device occurs to avoidgas supply shortage accidents and ensure user production, but also effectively prevent secondary accidents such as fan pressure holding, motor overload, tripping, high-pressure gas backflow impact, equipment damage, breaking of a water seal of a gas drainer and leakage of gas from happening.