Online review data can directly reflect the recreational experience and the quality of services of urban parks. Based on the background of the successive implementation of free policies in parks of Shanghai, I screened out the review data of the Shanghai Botanical Garden before and after free entry, and used content analysis and IPA analysis methods to construct a perceptual elements evaluation table and analysis model to compare the perceived differences in recreational experience before and after free admission. The results show: (1) The public’s overall satisfaction before admission is slightly higher than after it is free; (2) Natural landscapes, characteristic landscapes and entertainment projects are not affected by admission tickets, and tourists’ attention and satisfaction are always high. While tourists are always express dissatisfaction with the external transportation; (3) The perceived degree of the four elements of recreation cost, emotional experience, signage system and service level differs greatly before and after free admission. Based on the research results, targeted optimization strategies are proposed in these aspects of internal and external transportation, science popularization signs, and activity facilities, etc. This research can provide reference for the updated and optimized design of the Shanghai Botanical Garden, and provide reference for research on quality evaluation and users’ perception of recreational experience in urban specialized parks.