The invention discloses a photovoltaic power station design system. The system comprises a view-finding unit, an input unit, a calculation unit, a query unit, a data unit, a design unit and an output unit. The photovoltaic power station design system is arranged in a mobile terminal and a remote control center in communication connection with the mobile terminal; an outdoor scene of a house is photographed through the mobile terminal; and the length, width and orientation of the house are input, so that installed capacity design, electric design, plane layout chart design, vertical view design, bracket design and grid-connected mode design of a distributed photovoltaic power station can be realized by steps. The invention furthermore provides a design method for the photovoltaic power station design system. The size and orientation of the house or land can be input through the mobile terminal; the scene can be photographed through the mobile terminal; and the input information is calculated and designed to form a design detailed list and a layout of the photovoltaic power station. Compared with conventional manual design, the system has the advantages that the design is automatically finished by an intelligent device; and the use is convenient and quick, so that the photovoltaic system design efficiency is greatly improved.