Introduction: In an ageing society, older adults are the main users of healthcare services, and Chinese healthcare systems have been struggling to meet the care demand of older adults. Due to the illness, many older inpatients cannot finish daily activities independently and require healthcare from caregivers. Evaluating the care needs of older adults and exploring the factors affecting safe care at multiple levels are conducive to providing systematic care services for older inpatients. This study aims to examine which and how factors impact safe care for older inpatients and propose a safe care theory to provide directions on improving the safe care system in the hospital.

Methods and analysis: A mixed-methods study with three interrelated research streams will be designed. (1) A safe care concept model: we will conduct a scoping review to extract the facilitators and barriers influencing the safe care of older inpatients and construct a concept model based on the socio-ecological model and the Yorkshire Contributory Factors Framework. (2) A safe care theory model: we will conduct a qualitative study with thematic analysis (aimed at older inpatients, caregivers and nurses) to define the concept connotations and propose a theory model. (3) A safe care theory: we will use the scales related to the theory model to test the concepts and statements. We will revise the theory model and derive a safe care theory based on the mixed-methods study results. This study will start in October 2023 and end in October 2025.

Ethics and dissemination: This study was approved by the ethics committee (No. 20221598). All participants will be provided with consent forms prior to data collection. The study will be disseminated via peer-reviewed manuscripts and conferences.

Trial registration number: ChiCTR2300067421.