The invention discloses a detector for detecting the connection of an electronic device, which comprises a circuit board and a connector module; the circuit board comprises a power end and a signal processing unit; the connector module comprises a body and a detection part; the body is provided with a connecting end and a connecting side wall; the detection part is arranged on the connecting sidewall and is electrically connected with the power end and the signal processing unit, which is also provided with a voltage bit quasi. When an adapter of the electronic device is connected with a connection end, the adapter is contacted with the detection device to change the voltage level; and through the signal processing unit, changes of the voltage level can be detected to ensure that the electronic device is connected to the connector module.