Abstract: Doing a good job of cultivated land security evaluation and the diagnosis of obstacles affecting cultivated land security can effectively improve the current situation of cultivated land security and provide a basis for the sustainable development of cultivated land security. Based on the standardized processing of cultivated land data in Shandong Province from 2000 to 2020, entropy method and analytic hierarchy process are selected to determine the index weight. Based on DPSIR model, taking the cultivated land data of the past 20 years as the original data, the improved TOPSIS Model and obstacle model are applied to scientifically analyze the current situation of cultivated land security in Shandong Province and diagnose its obstacle factors. The research shows that: （1） In the past 20 years, the cultivated land security in Shandong Province has generally shown a stable and positive trend, but the evaluation index has been lower than 0.6; （2） From the perspective of dimensions, the driving force layer and influence layer show an upward trend, the pressure layer shows a downward trend, the changes of state layer and response layer are tortuous; （3） The pressure layer, state layer and influence layer have great influence on cultivated land security in Shandong Province, while the driving force layer and response layer have little influence; （4） The per capita agricultural output benefit, per capita GDP, the proportion of primary production, the proportion of agricultural employed population and the use of agricultural film are the main obstacle factors affecting the safety of cultivated land. Cultivated land protection policy, socio-economic development and scientific and technological progress will promote the change of cultivated land security obstacle factors.