The invention relates to the technical field of electrical engineering, in particular to a heat dissipation device for an electrical equipment room and the electrical equipment room. The heat dissipation device for the electrical equipment room comprises a cooling channel formed outside an accommodation space, wherein an air inlet end of the cooling channel is communicated with an air outlet in the electrical equipment room and an air outlet end of the cooling channel is communicated with an air inlet in the electrical equipment room, so as to form a closed air circulation channel with the accommodation space for cooling electrical equipment in the accommodation space, heat source air in the accommodation space is discharged through the air outlet and cooled when passing through the cooling channel and then returns to the accommodation space in a main room body through an air inlet of the main room body, air is in closed air circulation in the whole heat dissipation process, internal and external equivalent circulation of air is realized, air pressure in the electrical equipment room tends to be balanced, the situation of negative pressure in the room is avoided, and accordingly, foreign matter such as dust and the like can be prevented from entering the room and being accumulated to damage the electrical equipment due to negative pressure in the room.