In-person simulation is based on the simulated clinical situation, which embodies practical teaching methods, such as students' role playing, situation demonstration and teacher's guidance and feedback (LaFond and Van Hulle Vincent, 2013). The simulated clinical situation provides a safe and efficient learning environment (Zhu et al., 2022). In recent years, simulation has been extensively explored in the nursing education and achieved good results (Roh et al., 2013, Kim et al., 2016). This not only trains students' disease observation ability and nursing skills, but also improves their ability of nursing clinical thinking through cognition, analysis and problem-solving (Stenseth et al., 2022). The degree of students' participation plays an important role in the quality of situational simulation teaching (Kelly et al., 2016). Due to the limitations of case setting, class hours, manpower and equipment, it is very difficult for all students to participate in the simulation (Yang et al., 2016). What most students do is to observe and evaluate the performance of the students who get the chance to participate.

The computer-based virtual simulation (vSim) is the simulation of clinical situations by the use of the internet and virtual simulation technology (Berman et al., 2016), which enables a high degree of interaction and realism. In virtual simulation, when students visit the learning website, they can simulate the interaction between nursing staff and virtual patients. Students complete the nursing process through a series of decision-making choices or clinical skills to help them find the internal correlation of relevant theoretical knowledge points and promote the formation of clinical thinking (Conradi et al., 2009). Virtual simulation has such advantages as it is not subject to time and space limitations and allows repeated practice. In recent years, the teaching form based on virtualized patient system has been gradually applied in some medical colleges and affiliated hospitals and has achieved good results (Chen and Cao, 2023, Tang et al., 2018, Smith et al., 2014). However, the combination of virtual simulation and in-person simulation still lacks systematic research on improving students' comprehensive nursing ability.

In this study, we intended to combine virtual simulation with in-person simulation among undergraduate nursing students of a university in China. We introduced vSim as a preparation to in-person simulation of "Intestinal obstruction -- Nursing of patients with fluid and electrolyte imbalance" in the course of (Adult Nursing Science I). The objective of this study was to evaluate the effectiveness of virtual simulation plus in-person simulation among undergraduate nursing students. This will help us to improve the quality of simulation.