A fuel injection control device for a multi-fuel engine includes a corrector and a reviewer. An alcohol concentration learning unit is provided to learn an alcohol concentration in an injected fuel based on an oxygen concentration detected in an exhaust gas. A fuel injection amount controller is provided to control a fuel injection amount based on a learning value corresponding to the oxygen concentration. The corrector is configured to reduce the fuel injection amount corresponding to the learning value for a predetermined time period when the learning value is higher than a threshold value when an engine is started. The reviewer is configured to review the learning value to provide a revised learning value based on the oxygen concentration while the corrector reduces the fuel injection amount. The fuel injection amount is controlled based on the revised learning value after the corrector reduces the fuel injection amount.