In view of the digital technology growing vigorously, phones no longer used only for communication between people due to the rich functions of smartphones. People in public place focus on using cell phone and ignore the opportunities of interact with others, and this make people drift apart. Therefore, this paper tried to create friendly interaction for people through NFC smartphones and interactive installation, and encouraged people in public place to interact with each other, and made people feel warm and delighted in public place. First of all, this paper referred to the interactive modes of NFC phones, and researched in the influence of smartphones on interpersonal interaction in public place. Then this paper generalized the design principles according to the result of literature review, designed and implemented a multi-users collaborative interactive installation, named "EatFree." Finally during the public exhibition, this paper evaluated the result of combining NFC phones and collaborative interactive installation into interpersonal interaction in public place by observation, questionnaire and interview. This research discovered the following: 1) The operation mode and interaction mode of NFC smartphones are feasible to apply into interpersonal interaction. 2) Applying NFC smartphones into multi-users collaborative interactive installation is an innovative application. 3) The interactive installation developed by this study can improve the interpersonal interaction in public place. 4) The multi-users collaborative interactive installation combining with NFC smartphones can improve the enjoyment between people. 5) Multi-users collaborative interaction mode can enhance the feasibility of interpersonal interaction.