Urban parks are public green spaces which have a direct impact on the daily outdoor activities of residents and visitors due to their landscape and functionality. To enhance the spatial vitality and services of urban parks to meet the needs of urban residents and visitors, managers and planners should focus on people’s perceptions and preferences of park landscape characteristics. This study aimed to investigate the relationship between visitors’ landscape preferences and environmental factors in urban parks. Fixed-point photography and mobile measurements were used to quantify the environmental factors of urban parks. Unmanned aerial vehicle observations and ground observations were used to examine physical activities and spatial behaviors of visitors to quantify their landscape preferences. Second, the differences in visitors’ landscape preferences in various types of landscape spaces were analyzed based on descriptive statistics and significance tests. Finally, a correlation analysis and principal component analysis were introduced to explore the relationship between urban park environmental factors and visitors’ landscape preferences. The results showed that visitors’ physical activities and spatial behaviors were affected by many environmental factors, especially accessibility and visible green index. Our findings also shed new light on the significant differences in visitors’ physical activities and spatial behaviors of different genders and age groups. It was observed that most male visitors were sitting, whereas female visitors preferred to take photographs. Exploring the relationship between urban parks and visitors’ landscape preferences is of great significance for improving park satisfaction, people’s happiness, and urban sustainability.