Provided are a method for photovoltaic module fault diagnosis, an edge calculation processing device and an inverter. Firstly, multiple module-level power electronic devices are controlled to perform IV scanning on photovoltaic modules connected to the module-level power electronic devices respectively and IV curves of the photovoltaic modules are obtained by the module-level power electronic devices respectively. Secondly, an IV curve satisfying a condition is selected from the IV curves of the photovoltaic modules as a reference curve. Thirdly, each of remaining IV curves in the IV curves of the photovoltaic modules other than the reference curve is compared with the reference curve, to generate comparison results. Finally, a fault diagnosis result for each of the photovoltaic modules is generated based on the comparison results.