Flexible manufacturing is an important method for equipment manufacturing enterprises to interfere with manufacturing stability and enhance competitive advantage. Noting that the existing literature pays less attention to the quantification of manufacturing stability and manufacturing flexibility, in this paper, manufacturing qualification rate and manufacturing redundancy are used to describe manufacturing stability and manufacturing flexibility, on this basis, a unified analysis framework of manufacturing qualification rate, manufacturing flexibility and manufacturing profit of equipment manufacturing enterprises is constructed to investigate and reveal the influence of flexible manufacturing strategy on the stability of equipment manufacturing enterprises. The results show that: The launching of flexible manufacturing strategy can help equipment manufacturing enterprises to improve their ability to cope with environmental changes, ensure the quality and quantity of products, and then promote the growth of manufacturing profits;When the marginal cost of manufacturing is small, the level of manufacturing flexibility and the qualified rate of manufacturing show an inverted U-shaped trend; When the marginal cost of manufacturing is large, the level of manufacturing flexibility is positively correlated with the qualified rate of manufacturing; The increase of quality inspection marginal cost will force equipment manufacturing enterprises to reduce the level of manufacturing flexibility, and affect the ability of enterprises to deal with manufacturing stability, and ultimately lead to the loss of manufacturing profits.