In recent years, more and more households plan to tourist destinations or visit relatives on holidays. Facing the surging demand for household travel, this paper aims to explore the generation mechanism of household long-distance flexible travel on holidays. Firstly, a questionnaire survey on long-distance flexible travel behavior was conducted among middleincome households in first-and second-tier cities. Then, multiple endogenous and exogenous variables were extracted from the survey data. On this basis, a structural equation model (SEM) was established to analyze the influence of individual attributes, economic attributes, and household attributes over the travel attributes and travel intensity of household long-distance flexible travel. The results show that economic attributes had the greatest impact on travel intensity, among all exogenous variables. This means household income promotes the travel intensity, especially travel duration. Besides, household attributes negatively affect travel intensity. In other words, with the growing number of elderlies, children, and employed in the household, the number of travelers in household travel will increase, while the intensity of household travel will decline; the household will prefer to travel by car. The research results provide theoretical supports to the research of household flexible travel behavior, and enable tourist cities to effectively manage and optimize holiday traffic.