The article presents the results of historical and pedagogical research, the purpose of which was to identify the main features of the education of the least protected sectors of society in New Spain. The analysis of the authors of the original scientific and historical sources and scientific works of modern Latin American researchers allows us to draw the following conclusions. The education of the most marginalized populations in New Spain was in the interest of the Spanish crown and the Catholic Church. This was a state affair under the direct control of the Spanish monarchs, who in their hands signed a large number of orders on the study of the Law of God and the Castilian language of the indigenous population of the colonies and the opening of appropriate educational establishments, institutions for this purpose. So, already in the XVI century, the first schools for the Indians were initiated, where catechism was conducted by Catholic priests, first in the languages of local ethnic groups, and later only in Spanish. Based on the research, the authors found that the "sweeping" of the numerous ethnic groups in New Spain led to the loss of their identity and language. It has been established that the colonial economy was based on the exploitation of representatives of the conquered peoples. It has been noted that the Roman Catholic Church was the most important instrument of political and cultural influence on the Indians. As a result of studying the original documents, it was revealed that the Christianization of the Indians was carried out by creating conditions that justified the concession of the so-called western territories of the Spanish monarchy. It was found that the first attempt to introduce the formation of marginal groups of the population of New Spain can be called the decision of the Third Mexican Council (III Concilio Mexicano, 1585) on the compulsory study of the Indian language and the use of the monks for the local population evangelization, as well as royal orders for neighborhood. In total, the study found that the formation of the most vulnerable segments of the population in New Spain took place in two main directions: it served as a radical modification of material life (through the introduction of new technologies), as well as the transformation of spiritual existence (through a new religion).