A method and an integrated routing device for controlling remote systems via short messages are provided. When a mobile communication device controls remote systems via short messages, the method and the integrated routing device verify whether the mobile communication device is a legal commander. When the mobile communication device is verified as a legal commander, the method and the integrated routing device generate a verification code and subtract consumed time caused by message relay from a first control duration to generate a second control duration. The mobile communication device performs remote control during the second control duration. By completing above procedure, the method and the integrated routing device are capable of preventing fatal damages resulted from missing the right timing for executing control commands, and can further improve the efficiency of controlling remote systems via short messages.