Heat dissipation device of control cabinet

The invention discloses a heat dissipation device of a control cabinet. The heat dissipation device comprises a box body unit and a heat dissipation unit arranged in the box body unit, the heat dissipation unit comprises a ventilation assembly, a cooling water return assembly arranged on one side of the ventilation assembly and a control assembly arranged in the cooling water return assembly. The heat dissipation device has the beneficial effects that two heat dissipation means of ventilation and water cooling are added, and simultaneous opening and closing of the two heat dissipation means are achieved through the control assembly; according to the heat dissipation means, the temperature is used as a trigger signal, the temperature in the whole control cabinet can be accurately controlled in real time, and the phenomena that the temperature of the variable-pitch frequency converter in the variable-pitch control cabinet is too high, and consequently the variable-pitch frequency converter crashes and internal