The invention relates to a method for adjusting group transmission by the aid of GOOSE multicast and RS-485 broadcast cooperation, and belongs to the technical field of photovoltaic power generation. The method includes extending GOOSE service models on the basis of GOOSE service in IEC (international electrotechnical commission) 61850 standards by the aid of one-to-many GOOSE transmission mechanisms; defining LN as ZLSR; defining relevant DO key parameters of the ZLSR; multicasting photovoltaic power generation control data to each conversion device by the aid of the GOOSE transmission mechanisms; parsing and converting the received data by the aid of the conversion devices; broadcasting the data to each inverter by the aid of RS-485. The method has the advantages that photovoltaic active or reactive power can be regulated by each inverter according to the issued data in data packets, so that active or reactive power of integral photovoltaic power plants can be regulated, the power regulation response speeds can be obviously increased, fluctuation of power grids can be reduced, and the method has extremely high engineering practical value.