This study aims to explore the differences in people's situational awareness, trust, and acceptance of automation technology across different degrees of human-machine collaboration. It intends to provide valuable insights for the design and implementation of human-machine collaboration in future automation technology, ultimately enhancing operational efficiency, safety, and achieving effective human-automation system collaboration. Based on the OpenMATB experimental platform, 32 participants were recruited to complete tasks in four distinct levels of automation engagement. Comprehensive data on participants' situational awareness, trust, and acceptance of the automation system were recorded and then processed and analyzed to confirm the variations in the impact of different degrees of human-machine collaboration. The investigation showed a significant effect of human-machine collaboration on situational awareness. Initially, as system automation increased, situational awareness scores rose and then declined. Moreover, higher levels of human-machine collaboration were found to substantially boost trust and acceptance, as reflected by the corresponding score increases.