Background: Deer bone is rich in proteins and free amino acids, offering high nutritional value and benefits such as strengthening bones and antioxidant properties. However, the development and utilization of deer bone resources are limited, and the safety evaluation of health foods is incomplete. Methods: We established a hydrogen ethanol extraction method for deer bone and analyzed the components of the deer bone hydroethanolic extract (DBHE) using liquid chromatography–tandem mass spectrometry (LC-MS/MS), gas chromatography–mass spectrometry (GC-MS), and inductively coupled plasma mass spectrometry (ICP-MS). Results: Using Label-free proteomics technology, we identified 69 proteins and 181 peptides. We also quantified 16 amino acids, 22 fatty acids, and 17 inorganic elements. Finally, we evaluated the safety of DBHE both in vitro and in vivo. The results indicated that DBHE did not exhibit any toxic effects at the doses we tested and can promote the proliferation of mouse embryonic osteoblastic progenitor cells (MC3T3-E1), demonstrating potential efficacy against osteoporosis and arthritis. Conclusions: This study provides a theoretical basis for the quality control, processing, and resource development of deer bone.