To evaluate the application degree of the prefabricated steel structure technology in Gathering Station, particularly in small-scale permanent buildings for comprehensive duty rooms and integrated warehouses in the oil and gas field, an evaluation system for the applicability indicators of prefabricated steel structure technology is established from four perspectives: economic factors, environmental factors, social factors, and technical factors. The unascertained measure theory is introduced in this evaluation system. The G1-entropy weight method is utilized to calculate the combined weight of each indicator, and the applicability level of prefabricated steel structure in the gathering and transmission station is quantified and evaluated using the unascertained measure function, ensuring a scientific and effective determination of the applicability level. Finally, an analysis example is presented, focusing on a prefabricated steel structure shift apartment project in Guangyuan. The application study of this engineering example demonstrates that the unascertained measure model can be used to evaluate the applicability level. The evaluation results align with the actual situation, thus verifying the reliability and practicality of the aforementioned applicability degree evaluation method. Furthermore, it provides a reference for the application of prefabricated steel structure technology in similar scenarios.