The invention provides a detector for a junction box connector of a photovoltaic module, and belongs to the field of photovoltaic module detecting tools. The detector comprises a shell, a positive electrode testing part, a negative electrode testing part, a positive electrode pressure sensor, a negative electrode pressure sensor and an alarm module; the positive electrode testing part and the negative electrode testing part are arranged on the shell, the positive electrode testing part is provided with a first depth mark, and the negative electrode testing part is provided with a second depthpart; the outer diameter of the positive pressure sensor is greater than the standard inner diameter of a positive beryllium copper net, and the outer diameter of the negative pressure sensor is greater than the standard inner diameter of a negative metal core; the alarm module is arranged in the shell and is in communication connection with the positive pressure sensor and the negative pressure sensor. The detector provided by the invention does not need a universal meter, and has no direct relation with manual operation; a tensile machine is not needed, operation is convenient, and there isno destructive test; and visual inspection is not needed, inspection omission and mistakes are avoided, and the detector is convenient to carry.