The invention discloses a mounting base for improving heat radiation of a photovoltaic inverter. Transverse beams are fixedly connected with a same number of longitudinal beams for forming the base. The photovoltaic inverter is mounted on the base. Ground for mounting the base is provided with an outer trough and an inner trough. The bottom surface of the base is provided with a plurality of supporting mechanisms. The supporting mechanisms are placed in the inner trough and the outer trough. Each supporting mechanism comprises a supporting rod which is fixed on the bottom surface of the base, and a spherical roller at the end of the supporting rod. The circle center position of the outer trough and the inner trough is provided with a spacing hole. The bottom surface of the base is provided with a power shaft which extends into the spacing hole. The power shaft is provided with a driven gear. A motor is fixed on the ground. The output shaft of the motor is provided with a driving gear which engages with the driven gear. The mounting base is advantageous in that a photovoltaic plate can perform a sun shading function on the inverter for facilitating heat radiation; the photovoltaic plate fixes a base rotating structure; convenient mounting is realized; and purchasing of a large-size bearing is not required, thereby reducing construction cost.