The work aims to reconstruct the labor division, content and process of intra-city freight service, to improve the quality and efficiency of intra-city freight service and enrich the shippers' use experience. Non-participatory observation, questionnaire and interview methods were used to investigate the typical interactive behavior process of shipper and driver using the freight platform. Based on this, SAPAD theoretical model was applied to study the mapping relationship among the "behavior-meaning-object" of freight service. Then, through the clustering of the core meaning clusters, the four core requirements of user for intra-city freight service were deduced:order certainty, transaction efficiency, platform trust, and service professionalism. Finally, the labor division, content and process of service were re-planned based on the requirements, and the intra-city freight service framework was reconstructed. Based on the comprehensive behaviors of the shipper and the driver, qualitative and quantitative methods can be combined to sort out the core requirements in the complex service interaction process. The research results provide new ideas and methods for the optimization of the intra-city freight service design, and enrich the application practice of SAPAD in the multi-user field.