The invention discloses a photovoltaic assembly welding quality measurement device and a method for performing quality detection by applying the same, and relates to the technical field of a detection method for solar batteries. The method comprises the steps of performing equivalence on voltage and current values at a dry joint of an assembly through additionally arranging a current source for the assembly, performing multiple steps of adjustment on the device and a sampling element, enabling welding impedance of the assembly to be equivalent to an external circuit, sampling corresponding equivalent voltage and current, calculating a dry joint impedance value of the assembly, thus judging the welding quality of the assembly, and acquiring whether the assembly has a dry joint or not. The method disclosed by the invention does not damages the photovoltaic assembly, and is simple to operate, convenient to use, safe and reliable.