The article presented the authors’ simulator "Stupalki-LOGOS" (authors: M. M. Yefymenko, M. D. Moga) and considered the possibilities of its use in improving (correcting) the psycho-speech development of preschoolers with general underdevelopment of speech. The design of the simulator and the purpose of its three removable parts (handgrip handle, base platform, supporting surface of the simulator) are described. A brief classification of the main types of children’s hand disorders (hypotonic, hypertonic, dystonic, asymmetric) is made, and an algorithm for overcoming hand disorders according to each of the listed types is given. The main power hand functions that can be formed with the help of the Stupalki-LOGOS simulator (grab, supports, springs, rolling, balancing, stepping, etc.) are listed. The special role of the two-handed coordination function, which is formed due to this simulator, is emphasized. The cross-coordination of the upper and lower (when crawling) limbs forms the internal hemispheric neural networks necessary for brain activity for further left-hemisphere lateralization of the brain. The practical aspect of the research is presented in the article with sets of special exercises on the Stupalki-LOGOS simulator to improve the motor and psycho-speech development of preschoolers with general speech underdevelopment. The performed pedagogical observations proved that the "Stupalki-LOGOS" simulator improves the indicators of psycho-speech development: two-handed coordination improved, the basic power functions of the hand were formed (capture, supports, springs, rolling, stepping, pushing away), the state of mental well-being improved, as well as certain indicators of speech development (articulatory motor skills, phonetics, vocabulary).