A new approach to the treatment of wound lesions, which are complicated by the presence of polyresistant microflora and a possible immunodeficiency background has been proposed. It involves treating the wound surface with high-intensity pulsed optical radiation of a continuous spectrum, continuously covering the entire UV range (from 200 to 400 nm), visible and near infrared region of the spectrum. A pulsed xenon lamp is used as a radiation source. A description of the design and technical characteristics of the developed device for high-intensity optical irradiation "Zarnitsa-A", which implements the proposed medical technology for wound therapy, is represented. The results of preclinical studies of the apparatus in vitro and in vivo are represented hereinafter. The article shows that the apparatus exposure has pronounced bactericidal and wound-healing properties. The apparatus action reliably provides higher rates of wound healing compared to the use of only a typical antibacterial and wound healing agent – “Levomekol” ointment.