The invention discloses a distributed photovoltaic power station regional grid-connection protection system and a grid-connection control method. The distributed photovoltaic power station regional grid-connection protection system is connected between photovoltaic power stations and a transformer, and is characterized by comprising photovoltaic acquisition/control devices which communicate by means of electric carrier waves, a low-voltage comprehensive distribution box and a central control device, wherein the photovoltaic acquisition/control devices are connected with inverters of the photovoltaic power stations and used for acquiring parameters of the corresponding inverters, transmitting the acquired parameters to the central control device, receiving a command of the central control device and controlling the current generation power of the corresponding inverters; the low-voltage comprehensive distribution box is connected with the transformer and used for acquiring parameters of the transformer and transmitting the acquired parameters to the central control device; and the central control device acquires information in real time, calculates the residual power of the transformer and determines a grid-connection requirement according to the current generation power of the requesting photovoltaic power stations and the minimum adjustable active power, thereby solving problems of grid impact, photovoltaic power abandoning and the like generated by grid connection of power generation of a regional distributed photovoltaic power generation system, and protecting safe running of large power grid.