The invention discloses a photovoltaic assembly trimming device which comprises a workbench. An installation groove is formed in the middle of the workbench. A bottom hydraulic cylinder installation seat is arranged at the bottom of the installation groove. The upper side of a bottom electric hydraulic cylinder is connected with a supporting frame through a piston. Vacuum suction cups are arranged on the supporting frame. A vacuum pump is arranged on the lower right side of the workbench. Photovoltaic assembly conveying belts are arranged on the two sides of the installation groove. A left side trimming device is arranged on the upper side of a left side positioning device. A rear side trimming device is arranged on the upper side of a rear side positioning device. A right side trimming device is arranged on the upper side of a right side positioning device. A front side trimming device is arranged on the upper side of a front side positioning device. The photovoltaic assembly trimming device is novel in structure, by arranging four sets of trimming tools, EVA trimming removal can be conducted on the four edges of a photovoltaic assembly at the same time, and the trimming efficiency of the photovoltaic assembly is improved; and meanwhile, the positioning devices are arranged, photovoltaic assemblies of different dimensions can be positioned, the sizes of the photovoltaic assemblies can be judged, the dimension requirements of the different photovoltaic assemblies can be met, and the working speed of trimming is increased.