The invention provides a photovoltaic assembly used for a solar power generation system. The photovoltaic assembly used for the solar power generation system includes a transmitting glass piece, a solar battery, packaging material, a back board, a wiring box, a screw hole, a hooking piece and a connection bar, wherein the transmitting glass piece, the solar battery and the backboard form an assembled laminated piece through the packaging material and are arranged in a sequence of the transmitting glass piece, the packaging material, the solar battery, the packaging material, the backboard. Thephotovoltaic assembly is simple in structure, flexible in size, convenient and flexible in mounting. On one hand, a roof power generation unit can be changed into a proper size according to client demand. On the other hand, the integral color of the roof solar power generation system can be changed into a color such as red which is universally preferred by Chinese. At the same time, the system has a waterproof function. The bottom of the system is provided with a heat dissipation channel, so that the power generation efficiency can be stabled, the service life of the power generation system can be prolonged and the safety and reliability can be improved.