China's economy has gradually entered a new normal, the development speed has gradually stabilized, private enterprises market competition behavior also suffered.In order to adapt to the new economic situation, private enterprises optimize the state of internal organization and management, encourage employees to always maintain a full mood at work, and promote the improvement of production efficiency of enterprises.For employees, the salary that meets their expectations can make employees feel satisfied emotionally, which will directly affect whether employees are enthusiastic about completing work tasks and affect the overall work efficiency.In the case of better and better salary, employees feel that their work value is fully recognized, not only actively participate in the task, but also give full play to their potential according to their own abilities, so as to obtain higher work returns.Based on this, the research object is salary satisfaction and job performance of employees in private enterprises.This paper analyzes and discusses the relationship between them. In this process, we understand the methods and ideas adopted by scholars in studying the two variables, and recognize the importance of engagement in them.During the study, engagement was cited as a mediating variable and its mediating role was verified.In addition, in order to verify the relationship between variables, the research hypothesis was proposed and a balanced relationship model was built, and relevant survey data was obtained by means of questionnaire survey.The data results were imported into SPSS software, and the hypotheses were verified through actual investigation and analysis.The results show that there is a significant positive correlation between employee satisfaction and job performance in private enterprises.Employee salary satisfaction and job performance are positively correlated with the mediating variable of job engagement.The mediating role of job engagement in studying pay satisfaction and job performance is obvious.According to the research results, this paper understands that if private enterprises want to stimulate the enthusiasm of employees, strengthen internal management, and achieve the goal of transformation and upgrading as soon as possible, they need to pay attention to employees' salary satisfaction and job engagement.Recognition of job engagement acts as a mediator.The use of various salary management systems to improve the employee's work engagement, thereby affecting the employee's satisfaction with wages, so as to achieve the purpose of improving production efficiency.