The invention discloses a single-board assembly, a communication system, a handle bar wrench and an unlocking method of the handle bar wrench, and relates to the technical field of communications. Slide friction force between an unlocking hook and a panel in the unlocking process of a traditional handle bar wrench is avoided, so that unlocking is easier. The handle bar wrench comprises a wrench body and an unlocking mechanism, wherein the unlocking mechanism comprises an unlocking hook and a trigger; the unlocking hook is connected to the wrench body through a first rotary shaft in a rotary mode; the trigger is connected to the wrench body through a second rotary shaft in a rotary mode; the unlocking hook is provided with a first end and a second end; the first end is opposite to the second end, and the first rotary shaft is arranged between the first end and the second end; the first end is provided with a hook; the second end is provided with a first abutting portion; the trigger is provided with a second abutting portion; the first abutting portion makes contact with the second abutting portion; the second abutting portion is used for exerting first force on the first abutting portion when the trigger rotates around the second rotary shaft so that the unlocking hook can rotate around the first rotary shaft.