A control device of an internal combustion engine, comprising: - abnormal combustion prevention torque calculation means adapted to calculate an abnormal combustion prevention torque for preventing an abnormal combustion due to self-ignition whose heat source is a mixture of supplied fuel to the internal combustion engine and lubricant oil when a cylinder wall temperature of the internal combustion engine is at a low temperature, on the basis of the cylinder wall temperature or a temperature of a parameter in correlation with the cylinder wall temperature; - basic target torque calculation means adapted to calculate a basic target torque of the internal combustion engine on the basis of a load of the internal combustion engine; and - determination means adapted to determine whether the basic target torque is equal to or more than the abnormal combustion prevention torque, wherein: - a target torque of the internal combustion engine is set to the abnormal combustion prevention torque when the basic target torque is equal to or higher than the abnormal combustion prevention torque; - the target torque is set to the basic target torque when the basic target torque is lower than the abnormal combustion prevention torque; - the internal combustion engine is controlled so as a torque of the internal combustion engine to be the target torque; and - the abnormal combustion prevention torque calculation means is configured to calculate a predetermined fixed torque value as the abnormal combustion prevention torque when the cylinder wall temperature or the temperature of the parameter is equal to or below a predetermined value. - abnormal combustion prevention torque calculation means adapted to calculate an abnormal combustion prevention torque for preventing an abnormal combustion due to self-ignition whose heat source is a mixture of supplied fuel to the internal combustion engine and lubricant oil when a cylinder wall temperature of the internal combustion engine is at a low temperature, on the basis of the cylinder wall temperature or a temperature of a parameter in correlation with the cylinder wall temperature; - basic target torque calculation means adapted to calculate a basic target torque of the internal combustion engine on the basis of a load of the internal combustion engine; and - determination means adapted to determine whether the basic target torque is equal to or more than the abnormal combustion prevention torque, - a target torque of the internal combustion engine is set to the abnormal combustion prevention torque when the basic target torque is equal to or higher than the abnormal combustion prevention torque; - the target torque is set to the basic target torque when the basic target torque is lower than the abnormal combustion prevention torque; - the internal combustion engine is controlled so as a torque of the internal combustion engine to be the target torque; and - the abnormal combustion prevention torque calculation means is configured to calculate a predetermined fixed torque value as the abnormal combustion prevention torque when the cylinder wall temperature or the temperature of the parameter is equal to or below a predetermined value.