The invention provides a start control method of a photovoltaic grid-connected inverter following by inputting voltages. A voltage following control module can select a high voltage model channel composed of a high voltage inverting module and a high voltage regulating module or a low voltage model channel composed of a low voltage inverting module and a low voltage regulating module to share driving modules in accordance with the input voltages detected by the voltage following control module. The method is used for solving the problems that the starting voltage of the existing medium and high power photovoltaic grid-connected inverter is too high and a low input voltage section of a photovoltaic module cannot be effectively utilized. The system has two groups of inverting modules and regulating modules, the starting voltage of the system can be easily realized a seamless connection, the generation resource of the modules can be utilized maximally, and the overall inversion efficiency of the system can be improved. A group of driving modules are used for respectively driving two groups of inverting modules without artificial interferences, a set value is given only, and the system detects the coincident conditions, the system can automatically switch.