The invention provides a temperature rise test system and method for a photovoltaic inverter in a field operation condition. The system comprises a signal transceiver antenna, a signal acquisition controller, and passive wireless temperature sensors installed at a plurality of test points in a photovoltaic inverter cabinet and connected to the plurality of test points one to one. The passive wireless temperature sensors are connected to the signal acquisition controller through the signal transceiver antenna in a radiofrequency manner. The signal acquisition controller further includes a calculation module configured to calculate the temperature rise values of respective components in the inverter cabinet according to results measured by the passive wireless temperature sensors. The systemuses the passive wireless temperature sensors using radiofrequency identification technology, can realize simultaneous measurement of multiple external temperature points in the cabinet and temperature points outside the cabinet under the normal operating condition of the photovoltaic inverter, and enables an inverter to operate in a maximum output power operating state by a DC input square matrix combining method, thereby obtaining the maximum operation temperature rise of the inverter.