The invention discloses a space-adjustable multi-functional power cabinet. The space-adjustable multi-functional power cabinet comprises a cabinet body, a second cabinet body, a power-driven push rod,a first ventilation net, a rain cover, a second ventilation net, a motor, a crank shaft, a first connection rod shaft neck, a first sleeve, a first connection rod, a movable rod and a brush. The cabinet body, the second cabinet body and the power-driven push rod are arranged, the height of the second cabinet body can be adjusted by the power-driven push rod, so that the volume of the whole powercabinet is adjusted, the space is fully utilized, and moreover, power equipment with different volumes can be installed; the space-adjustable multi-functional power cabinet is high in applicability; and the motor, the crank shaft, the first connection rod shaft neck, the first sleeve, the first connection rod, the movable rod and the brush are arranged, the second ventilation net is continuously brushed by the brush in a matching way, the second ventilation net is prevented from being plugged with dust, heat dissipation is facilitated, and the cooling efficiency is improved.