The seafloor hosts a large number of biological communities, and scientific research on these marine benthic organisms is an important means for mankind to understand and study the evolution of marine life and the seafloor environment. Currently, it is easy to cause damage to seafloor fish during capture, especially soft-bodied fish, resulting in high mortality rates. In order to simulate the damage, accurate mechanical properties and finite element models of different parts of the fish are needed so that sampling gear can be better designed and the fish can be protected from severe damage. In addition, from a bionic perspective, accurate biomechanical properties are needed for better design of bionic gear. In this paper, the head, body and tail of the dragon head fish were compressed by universal testing machine, and the stress-strain curves of different parts of the dragon head fish and the ultimate stress and strain of each experimental group were obtained. According to the superelastic and incompressible characteristics of biological tissue materials, the hyperelastic model was used to fit the materials of different parts of the dragon head fish. The constitutive models of different parts of the dragon head fish were obtained. Finally, the finite element analysis software is used to simulate the collision process of deep-sea molluscs. The analysis results show that the stress in the skull is the largest, and the stress is concentrated at the contact position between the skull and the titanium alloy plate. The strains in the soft tissue are liver, stomach, fish gill and egg in descending order. The results of this study are essential for developing the finite element model of fish, which can be further applied to impact biomechanics, biomedicine and bionics.