This research aims to study the objectives of this study are as follows: (1) to purpose mediating effect of leadership and cost control between external environment and organization structure of the tourism industry in Tongliao city inner Mongolia autonomous region the people’s republic of china. (2) To investigate the factor direct and indirect among external environment and organization structure of the tourism industry in Tongliao city inner Mongolia autonomous region the people’s republic of china. This study adopts a mixed- method approach combining quantitative and qualitative methods. The quantitative study surveyed 2,851 employees from 35 SMEs in the tourism industry in Tongliao City, Inner Mongolia Autonomous Region, China, through questionnaire surveys, with a sample of 400 employees. The qualitative research method involved in-depth interviews with 3 senior management personnel. Major Findings: To investigate and analyze the causal factors influencing the organizational structure of the tourism industry in Tongliao City, Inner Mongolia Autonomous Region, People's Republic of China, this study conducted a detailed analysis based on the structural equation model shown in the image. According to the model results, the Chi-square value is 248.663, the degrees of freedom are 106, the CMIN/df is 2.346, the sample size is 400, the CFI is 0.954, the NFI is 0.924, the GFI is 0.951, the IFI is 0.955, the RMSEA is 0.043, and the SRMR is 0.048. These indicators demonstrate a good model fit. Specifically, the key influencing factors include Leadership (LEA), Organizational Resources (ORS), Employee Efficiency (EE), and Cultural Construction (CCL). Among them, the impact coefficient of Leadership on Organizational Resources is 0.52, the impact coefficient of Organizational Resources on Employee Efficiency is 0.63, and the impact coefficient of Employee Efficiency on Cultural Construction is 0.75. Additionally, Leadership indirectly influences Cultural Construction through Organizational Resources. These causal relationship data provide important references for optimizing the organizational structure of the tourism industry in Tongliao City.