The invention discloses a photovoltaic module mounting structure and a photovoltaic system. The photovoltaic module mounting structure includes a frame and a bracket, the bracket is provided with a first sliding portion, the frame includes two first frames that are oppositely disposed, the first frame includes a body and a second sliding portion, and the second sliding portion is disposed at the bottom portion of the body, and the second sliding portion is configured to form sliding fit with the first sliding portion in the longitudinal direction of the first frame, and the bottom of the bodycan abut against the bracket. The frame and the bracket of the photovoltaic component mounting structure are in sliding fit with no need for matching installation of bolts and pressing blocks, the installation is convenient, and the efficiency is high; the bolts or pressing blocks are not required, the stress concentration of the frame and the bracket of the photovoltaic module can be reduced, andthe strength can be improved; and moreover, after the frame of the photovoltaic module is matched with the bracket, the bottom of the first frame can be abutted against the bracket to improve the fixing effect of the frame and the bracket of the photovoltaic module and have the better stability.