Neighbourhood parks are an essential activity venue for contemporary older adults and potentially impact their health. Most research has focused on the physical and visual dimensions of the park, with some studies demonstrating differences in the visual preferences of gender. Still, there is a lack of detailed research on the social and perceptual dimensions of male and female older people and a lack of research on psycho-emotional satisfaction and mechanisms to alleviate the psychological isolation of older people of different genders. In this study, a mixed research method was conducted to investigate the multi-dimensional interaction of older people using neighbourhood park, with a sample size of 418 participants from the Chaoyang district of Beijing, an integrated research method including questionnaires, semi-structured interviews and observation, Goodman and Kruskal’s gamma analysis and Grounded theory qualitative method applied by using SPSS and NVivo to analyse the elements of neighbourhood parks related psychological outcomes. A conceptual framework of multi-layered social interactions and the influence of different social interactions on the perceptual and psychological dimensions has been conducted, as well as the gender differences. The study found that the social, physical space and perceptual dimensions of neighbourhood parks all contribute to alleviating loneliness among older people, that site-based self-regulation also plays an important role, and that low-level social interactions generally affect older people. In contrast, mid-level social interactions have a significant effect on perceptual and psychological benefits, with a synergistic increase in impact, and older women show a more vital need for social activities and self-expression than men. The findings of this study provide a theoretical basis for a multidimensional spatial mediation to enhance the well-being of older people and provide new ideas for comprehensive multidimensional and multi-level ageing optimisation research.