The changes taking place at the present stage require adequate changes in the assessment of the sustainable development of small business, allowing to reduce risks and ensure a sufficient level of financial stability of companies, which determines the relevance of the issues under consideration. The aim of the study is to identify methods for ensuring sustainable development of entrepreneurship, which will qualitatively model the processes of making financial decisions under conditions of uncertainty. The study forms a logical structure for sustainable development of entrepreneurship, which establishes a certain set of rules for the strategy to achieve the goal of the system. In the presence of uncertainty, there is a risk of ineffective management, in which the planned goals are not achieved. These questions can be solved based on the fuzzy logic model. A model of fuzzy sets for sustainable development of entrepreneurship is proposed, with the help of which a business entity can model variations in the development of entrepreneurial initiative, identify strengths and weaknesses and compare alternative options for doing business. The stages of implementation of the proposed fuzzy logic model are described in detail. The options for identifying the current state of the company with the interpretation of the conditions for diagnosing the financial state of the company are considered. Studies have shown the possibility of effective use of the principles of fuzzy logic and modeling in solving problems of developing entrepreneurial potential and making management decisions in conditions of uncertainty.