A detachable robot system includes a mobile working machine and an intelligent device. The mobile working machine includes a transmission wheel device, a first fastening portion and a first conductive contact. The first fastening portion and the transmission wheel device are oppositely arranged on the first main body. The transmission wheel device loads and moves the first main body. The intelligent device is completely removable from the mobile working machine, and includes a second fastening portion and a second conductive contact. Thus, when the intelligent device is loaded on the mobile working machine, the intelligent device is fixedly coupled to the mobile working machine by the first fastening portion and the second fastening portion engaged with each other, so that the first conductive contact and the second conductive contact are aligned and connected to each other.